Even if the world is full of counterfeits, I still regard it as wonderful.

Pile up herbs and incense, and arise again from the flames and ashes of its predecessor — as is known to many, the phoenix does it like this.

The phoenix has a rather long lifespan, and reincarnates itself once every a! years. Here a! denotes the factorial of integer a, that is, a! = 1 × 2 × ... × a. Specifically, 0! = 1.

Koyomi doesn't care much about this, but before he gets into another mess with oddities, he is interested in the number of times the phoenix will reincarnate in a timespan of b! years, that is, <image>. Note that when b ≥ a this value is always integer.

As the answer can be quite large, it would be enough for Koyomi just to know the last digit of the answer in decimal representation. And you're here to provide Koyomi with this knowledge.

Input

The first and only line of input contains two space-separated integers a and b (0 ≤ a ≤ b ≤ 1018).

Output

Output one line containing a single decimal digit — the last digit of the value that interests Koyomi.

Examples

Input

2 4


Output

2


Input

0 10


Output

0


Input

107 109


Output

2

Note

In the first example, the last digit of <image> is 2;

In the second example, the last digit of <image> is 0;

In the third example, the last digit of <image> is 2.
      import java.util.*; 
                                            import java.math.*;
                                            import java.io.*;
                                            import java.text.DecimalFormat;
                                            import java.math.BigInteger;
                                            public class Main{
                                                //static int d=20;
                                                static long mod=1000000007 ;
                                                
                                                static ArrayList<ArrayList<Integer>> arr;
                                               // static long[] dp1,dp2;
                                                static int[] a;
                                                static int[] vis,num;
                                                static long max;
                                                static HashSet<String> hs;
                                                //static int flag,ans;
                                                static long max1,max2,ans1;
                                                
                                                static int flag=0;
                                                static int[] tin,tout,parent,level;
                                                static HashMap<Long,Integer> hm;
                                                static long[] dp1,dp2,dp3,dp4;
                                                   
                                                public static void main(String[] args)  throws IOException {
                                                    ///long start=System.currentTimeMillis();
                                                    boolean online =false;
                                                    String fileName = "B-small-attempt0";
                                                    PrintWriter out; 
                                                    if (online) {
                                                        s.init(new FileInputStream(new File("Downloads/"+fileName + ".in")));
                                                         out= new PrintWriter(new FileWriter(fileName + "out.txt"));
                                                    }
                                                     else {
                                                        s.init(System.in);   
                                                    
                                                        out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
                                                        //out= new PrintWriter(new FileWriter(fileName + "out.txt"));
                                                    }//r,b,y,g
                                                    long a=s.nl();
                                                    long b=s.nl();
                                                    long ans=1;
                                                    for(long i=a+1;i<=b;i++){
                                                        ans*=i;
                                                        ans%=10;
                                                        if(ans==0)
                                                            break;
                                                    }
                                                    out.println(ans);
                                                    out.close();
                                                        
                                                      
                                                            
                                            
                                                }
                                               
                                                

                                                public static void union(int[] a,int x,int y){
                                                    int u=find(a,x);
                                                    int v=find(a,y);
                                                    a[v]=u;

                                                }
                                                public static int find(int[] a,int x){
                                                    if(a[x]!=x){
                                                        a[x]=find(a,a[x]);
                                                    }
                                                    return a[x];
                                                }
                                                public static int gcd(int a, int b){
                                                        if (a == 0) return b;
                                                        return gcd(b % a, a);
                                                }
                                                    
                                                public static void cfs(ArrayList<HashSet<Integer>> arr,int c,int p,int g,int[] vis){
                                                    vis[c]=1;
                                                    if(g!=-1){
                                                        if(!arr.get(c).contains(g)){
                                                            flag=1;
                                                            return;
                                                        }
                                                    }
                                                    for(int x:arr.get(c)){
                                                        if(x!=p && x!=g && vis[x]==0 ){
                                                            cfs(arr,x,c,p,vis);
                                                        }
                                                    }
         
                                                }
                                                                      //   public static void dfs(int u,int p){
                 //                            //       if(p>=0)
                 //                            //           tin[u]=tout[u]=tt++;
                 //                            //       if(p>=0)
                 //                            //           level[u]=level[p]+1;
                 //                            //       parent[u]=p;
                 //                            //       for(int x:arr.get(u)){
                 //                            //           if(x!=p){
                 //                            //               dfs(x,u);
                 //                            //               tout[u]=Math.max(tout[u],tout[x]);
                 //                            //           }
                 //                            //       }
                 //                            //       
                 //
                 //
                                             //   }
                                                public static int lca(int[][] p,int a,int b){
                                                    if(level[a]<level[b]){
                                                        int x=a;
                                                        a=b;
                                                        b=x;
                                                    }
                                                    int log=p[0].length;
                                                    for(int i=log-1;i>=0;i--){
                                                        if(1<<i<=level[a]-level[b]){
                                                            a=p[a][i];
                                                        }
                                                    }
                                                    if(a==b)
                                                        return a;
                                                    for(int i=log-1;i>=0;i--){
                                                        if(p[a][i]!=p[b][i]){
                                                            a=p[a][i];
                                                            b=p[b][i];
                                                        }
                                                    }
                                                    return p[a][0];
                 
                                                }
                                                public static int[][] par(int[] parent){
                                                    int n=arr.size();
                                                    int[][] p=new int[n][17];
                                                    for(int i=0;i<n;i++)
                                                        p[i][0]=parent[i];
                                                    for(int k=1;k<17;k++){
                                                        for(int i=0;i<n;i++){
                                                            if(p[i][k-1]>-1)
                                                                p[i][k]=p[p[i][k-1]][k-1];
                                                            else
                                                                p[i][k]=-1;
                                                        }
                                                    }
                                                    return p;
                                                }
                                                static class Edge implements Comparable<Edge>{
                                                       int from;
                                                        int to;
                                                        long cost;
                                                
                                                       public Edge(int from, int to, long weight) {
                                                           this.from = from;
                                                           this.to = to;
                                                           this.cost= weight;
                                                       }
                                                       public int compareTo(Edge o){
                                                            return (int)Math.signum(cost-o.cost); 
                                                       }

                                                }                               
                                                static class Node {
                                                    int start;
                                                    int end;
                                
                                                    int cost;
                                                    int updated;
                                
                                                    Node[] nodes;
                                
                                                    public Node(int start, int end) {
                                                        this.start = start;
                                                        this.end = end;
                                
                                                        if (start < end) {
                                                            int[] pos = {start, (start + end) / 2, end};
                                                            nodes = new Node[2];
                                                            for (int i = 0; i < 2; i++) {
                                                                nodes[i] = new Node(pos[i] + i, pos[i + 1]);
                                                            }
                                                        }
                                                    }
                                
                                                    public void update(int queryStart, int queryEnd, int value) {
                                                        if (queryEnd < start || end < queryStart) {
                                                            return;
                                                        }
                                
                                                        if (queryStart <= start && end <= queryEnd) {
                                                            cost += value;
                                                            updated += value;
                                                            return;
                                                        }
                                
                                                        propagate();
                                                        for (Node node: nodes) {
                                                            node.update(queryStart, queryEnd, value);
                                                        }
                                                    }
                                
                                                    public int query(int pos) {
                                                        if (pos < start || end < pos) {
                                                            return 0;
                                                        }
                                
                                                        if (start == end) {
                                                            return cost;
                                                        }
                                
                                                        propagate();
                                                        int ans = 0;
                                                        for (Node node: nodes) {
                                                            ans = Math.max(ans, node.query(pos));
                                                        }
                                                        return ans;
                                                    }
                                
                                                    public void propagate() {
                                                        if (updated != 0 && start < end) {
                                                            for (Node node: nodes) {
                                                                node.cost += updated;
                                                                node.updated += updated;
                                                            }
                                                            updated = 0;
                                                        }
                                                    }
                                                }
                                                public static double nthroot(int n, double A) {
                                                    return nthroot(n, A, 0.0000001);
                                                }
                                                public static double nthroot(int n, double A, double p) {
                                                    if(A < 0) {
                                                        System.err.println("A < 0");// we handle only real positive numbers
                                                        return -1;
                                                    } else if(A == 0) {
                                                        return 0;
                                                    }
                                                    double x_prev = A;
                                                    double x = A / n;  // starting "guessed" value...
                                                    while(Math.abs(x - x_prev) > p) {
                                                        x_prev = x;
                                                        x = ((n - 1.0) * x + A / Math.pow(x, n - 1.0)) / n;
                                                    }
                                                    return x;
                                                }
                                                
                                                static class item implements Comparable<item> {
                                                    int from,to,cost;
                                                    public item(int x,int y){
                                                        from=x;
                                                        to=y;
                                                        
                                                    }
                                                    public int compareTo(item o){
                                                        
                                                        return  o.cost-cost;
                                                    }
                                                    
                                                }
                                               
                                                public static void dfs2(int c,int p,int[] a){
                                                    //System.out.println(c+" "+p);
                                                   
                                                    
                                                    
                         
                                                }
                //public static void dfs(int x,int[] vis,Stack<Integer> st){
                                                //    vis[x]=1;
                                                //    ArrayList<Integer> arr2=arr.get(x);
                                                //    Collections.sort(arr2);
                                                //    for(int i=arr2.size()-1;i>=0;i--){
                                                //        int z=arr2.get(i);
                                                //        if(vis[z]==0)
                                                //            dfs(z,vis,st);
                                                //    }
                                                //    st.push(x);
                         //
                                                //}
                                                public static long gcd(long a, long b){
                                                        if (a == 0) return b;
                                                        return gcd(b % a, a);
                                                }
                                                    
                                                public static boolean check(long x){
                                                    if(x%4==0 || x%7==0 || x%11==0)
                                                        return true;
                                                    if(x<4 || x<7 || x<11)
                                                        return false;
                                                    if(x%2==0){
                                                        return check(x/2);
                                                    }
                                                    else
                                                        return check(x/2) && check((x+1)/2);
                                                }
                                                public static int angle(int x1,int x2,int x3,int y1,int y2,int y3){
                                                    long val=(y2-y1)*1L*(x3-x2)-(y3-y2)*1L*(x2-x1);
                                                    if(val<0)
                                                        return 1;
                                                    else if(val>0)
                                                        return -1;
                                                    else
                                                        return 0;
                                                }
                                                
                                                static class BIT{
                                                
                                                    int N;
                                                    long tree[];
                                                    
                                                    BIT(int N){
                                                        this.N = N;
                                                        tree = new long[N + 1];
                                                    }
                                                    
                                                    void update(int idx,long val){
                                                        while(idx <= N){
                                                            tree[idx]+=val;
                                                            idx += (idx & -idx);
                                                        }
                                                    }
                                                    
                                                    long query(int l,int r){
                                                        if(l == 1)
                                                            return read(r);
                                                        else
                                                            return read(r) - read(l-1);
                                                    }
                                                    
                                                    long read(int idx){
                                                        long sum = 0;
                                                        while(idx > 0){
                                                            sum += tree[idx];
                                                            idx -= (idx & -idx);
                                                        }
                                                        return sum;
                                                    }
                                                }
                                                public static boolean pal(String a){
                                                    int i=0;
                                                    int j=a.length()-1;
                                                    while(i<j){
                                                        if(a.charAt(i)!=a.charAt(j)){
                                                            return false;
                                                        }
                                                        i++;
                                                        j--;
                                                    }
                                                    return true;
                                                        
                                                }
                                                public static long find(long n,long k){
                                                    if(n==2){
                                                        if(k==1 || k==3)
                                                            return 1;
                                                        else
                                                            return 2;
                                                    }
                                                    long t=pow2(2,n,mod)-1;
                                                    long z=(t+1)/2;
                                                    if(k==z)
                                                        return n;
                                                    if(k<z)
                                                        return find(n-1,k);
                                                    else
                                                        return find(n-1,k-z);
                                                }
                                                public static long pow2(long a,long b,long mod){
                                                        
                                                        long ans=1;
                                                       // long z=b;
                                                        while(b>0){
                                                           
                                                            if(b%2==1)
                                                                ans=(a*ans)%mod;
                                                            a=(a*a)%mod;
                                                            b/=2;
                                                        }
                                                      
                                                        return  ans;
                                                }
                                                 public static long pow3(long a,long b){
                                                        
                                                        long ans=1;
                                                       // long z=b;
                                                        while(b>0){
                                                           
                                                            if(b%2==1)
                                                                ans=(a*ans);
                                                            a=(a*a);
                                                            b/=2;
                                                        }
                                                      
                                                        return  ans;
                                                }
                                                public static long fib(long n){
                                                    long[][]    f=new long[][]{{1L,1L},{1L,0}};
                                                    if(n==0)
                                                        return 0;
                                                    f=arrpow(f,n-1);
                                                    return f[0][0];
                                                }
                                                public static long[][] arrpow(long[][] a,long b){
                                                   
                                                        int n=a.length;
                                                      //  long z=b;
                                                        long[][] ans=new long[n][n];
                                                        for(int i=0;i<n;i++)
                                                            ans[i][i]=1L;
                                                        while(b>0){
                                                            
                                                            if(b%2==1)
                                                                ans=mul(a,ans);
                                                            a=mul(a,a);
                                                            b/=2;
                                                        }
                                                        
                                                        return  ans;
                                                }
                                                public static long[][] mul(long[][] a,long[][] b){
                                                    int n=a.length;
                                                    int m=b[0].length;
                                                    long[][] ans=new long[n][m];
                                                    if(n==2 && m==2 && b.length==2){
                                                        ans[0][0]=((a[0][0]*b[0][0])%mod+(a[0][1]*b[1][0]))%mod;
                                                        ans[0][1]=((a[0][0]*b[0][1])%mod+(a[0][1]*b[1][1]))%mod;
                                                        ans[1][0]=((a[1][0]*b[0][0])%mod+(a[1][1]*b[1][0]))%mod;
                                                        ans[1][1]=((a[1][1]*b[1][1])%mod+(a[1][0]*b[0][1]))%mod;
                                                        return ans;
                     
                                                    }
                                                    for(int i=0;i<n;i++){
                                                        for(int j=0;j<m;j++){
                                                            for(int k=0;k<b.length;k++){
                                                                ans[i][j]=(ans[i][j]+(a[i][k]*b[k][j])%mod)%mod;
                                                            }
                                                        }
                                                    }
                                                    return ans; 
                                                }
                                                 static class name implements Comparable<name> {
                                                    long l,b,h;
                                                    public name(long   x,long y,long z){
                                                        {
                                                            l=x;
                                                            b=y;        
                                                        }
                                                        
                                                        
                                                        h=z;
                                                    }
                                                    public int compareTo(name o){
                                                        return -(int)(l*b-o.l*o.b);
                                                    }
                                                    
                                                }
                                                public static class s {
                                                    static BufferedReader reader;
                                                    static StringTokenizer tokenizer;
                                                
                                                    /** call this method to initialize reader for InputStream */
                                                    static void init(InputStream input) {
                                                        reader = new BufferedReader(
                                                                    new InputStreamReader(input) );
                                                        tokenizer = new StringTokenizer("");
                                                    }   
                                                
                                                    /** get next word */
                                                    static String ns() throws IOException {
                                                        while ( ! tokenizer.hasMoreTokens() ) {
                                                            //TODO add check for eof if necessary
                                                            tokenizer = new StringTokenizer(
                                                                reader.readLine() );
                                                        }
                                                        return tokenizer.nextToken();
                                                    }
                                                
                                                    static int ni() throws IOException {
                                                        return Integer.parseInt( ns() );
                                                    }
                                                
                                                    static double nd() throws IOException {
                                                        return Double.parseDouble( ns() );
                                                    }
                                                    static long nl() throws IOException {
                                                        return Long.parseLong( ns() );
                                                    }
                                                }
                                            }   
