Two little greedy bears have found two pieces of cheese in the forest of weight a and b grams, correspondingly. The bears are so greedy that they are ready to fight for the larger piece. That's where the fox comes in and starts the dialog: "Little bears, wait a little, I want to make your pieces equal" "Come off it fox, how are you going to do that?", the curious bears asked. "It's easy", said the fox. "If the mass of a certain piece is divisible by two, then I can eat exactly a half of the piece. If the mass of a certain piece is divisible by three, then I can eat exactly two-thirds, and if the mass is divisible by five, then I can eat four-fifths. I'll eat a little here and there and make the pieces equal". 

The little bears realize that the fox's proposal contains a catch. But at the same time they realize that they can not make the two pieces equal themselves. So they agreed to her proposal, but on one condition: the fox should make the pieces equal as quickly as possible. Find the minimum number of operations the fox needs to make pieces equal.

Input

The first line contains two space-separated integers a and b (1 ≤ a, b ≤ 109). 

Output

If the fox is lying to the little bears and it is impossible to make the pieces equal, print -1. Otherwise, print the required minimum number of operations. If the pieces of the cheese are initially equal, the required number is 0.

Examples

Input

15 20


Output

3


Input

14 8


Output

-1


Input

6 6


Output

0
// Don't place your source in a package
import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*; 
 

 
 
 
 
// Please name your class Main
public class Main {
	
	//static StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
 
    /*static int read() throws IOException {
        in.nextToken();
        return (int) in.nval;
    }
    static String readString() throws IOException {
        in.nextToken();
        return in.sval;
	}*/
	
	
	static Scanner in = new Scanner(System.in);
	
	public static void main (String[] args) throws java.lang.Exception {
	    
		//InputReader in = new InputReader(System.in);
		PrintWriter out = new PrintWriter(System.out);
		
 
		int T=1;
		
		for(int t=0;t<T;t++){
			int a=Int();int b=Int();
			
			Solution sol=new Solution();
			sol.solution(a,b);
		}
 
		out.flush();
	}
	
	
	
	public static long Long(){
		return in.nextLong();
	}
	public static int Int(){
		return in.nextInt();
	}
	public static String Str(){
		return in.next();
	}
}
 
class Solution{
	//constant variable
	final int MAX=Integer.MAX_VALUE;
	final int MIN=Integer.MIN_VALUE;
	//Set<Integer>adjecent[];
	//////////////////////////////
 
	public void fastprint(PrintWriter out,String s){
		out.print(s);
	}
	
	public void fastprintln(PrintWriter out,String s){
		out.println(s);
	}

	
	
	
	public void solution(int a,int b){
		int res=0;
		
		int A[]=new int[3];
		int B[]=new int[3];
		
		while(a%2==0){
			a/=2;
			A[0]++;
		}
		while(a%3==0){
			a/=3;
			A[1]++;
		}
		while(a%5==0){
			a/=5;
			A[2]++;
		}
		
		while(b%2==0){
			b/=2;
			B[0]++;
		}
		while(b%3==0){
			b/=3;
			B[1]++;
		}
		while(b%5==0){
			b/=5;
			B[2]++;
		}
		
		if(a!=b){
			msg("-1");return;
		}
		
		res+=(Math.max(A[0],B[0])-Math.min(A[0],B[0]));
		res+=(Math.max(A[1],B[1])-Math.min(A[1],B[1]));
		res+=(Math.max(A[2],B[2])-Math.min(A[2],B[2]));
		msg(res+"");
	}

	

	

	
	
	
	
	
	
	
	
	
	/*public void delete(Dnode node){
		Dnode pre=node.pre;
		Dnode next=node.next;
		pre.next=next;
		next.pre=pre;
		map.remove(node.v);
	}
	
	public void add(int v){
		Dnode node=new Dnode(v);
		Dnode pre=tail.pre;
		pre.next=node;
		node.pre=pre;
		node.next=tail;
		tail.pre=node;
		map.put(v,node);
	}
	
	class Dnode{
		Dnode next=null;
		Dnode pre=null;
		int v;
		public Dnode(int v){
			this.v=v;
		}
		
	}*/
 
 
 
 
	public void sort(int A[]){
		Arrays.sort(A);
	}
	
	public void swap(int A[],int l,int r){
		int t=A[l];
		A[l]=A[r];
		A[r]=t;
	}
	
 
	
	
	public long C(long fact[],int i,int j){ // C(20,3)=20!/(17!*3!)
		// take   a/b     where a=20!  b=17!*3!
		if(j>i)return 1;
		if(j<=0)return 1;
		long mod=998244353;
		long a=fact[i];
		long b=((fact[i-j]%mod)*(fact[j]%mod))%mod;
		BigInteger B= BigInteger.valueOf(b);
		long binverse=B.modInverse(BigInteger.valueOf(mod)).longValue();
		return ((a)*(binverse%mod))%mod;
	}
	
	public long gcd(long a, long b) 
    { 
        if (a == 0) 
            return b; 
        return gcd(b%a, a); 
    } 
	
	 
	
	//map operation
	public void put(Map<Integer,Integer>map,int i){
		if(!map.containsKey(i))map.put(i,0);
		map.put(i,map.get(i)+1);
	}
	
	public void delete(Map<Integer,Integer>map,int i){
		map.put(i,map.get(i)-1);
		if(map.get(i)==0)map.remove(i);
	}
 
 
 
 
 
	
 
 
	/*public void tarjan(int p,int r){
		if(cut)return;
		List<Integer>childs=adjecent[r];
		dis[r]=low[r]=time;
		time++;
		
		//core for tarjan
		int son=0;
		for(int c:childs){
			if(ban==c||c==p)continue;
			if(dis[c]==-1){
				son++;
				tarjan(r,c);
				low[r]=Math.min(low[r],low[c]);
				if((r==root&&son>1)||(low[c]>=dis[r]&&r!=root)){
					cut=true;
					return;
				}
			}else{
				if(c!=p){
					low[r]=Math.min(low[r],dis[c]);
				}
			}
		}
		
	}*/
	
	
 
	
	//helper function I would use
	public void remove(Map<Integer,Integer>map,int i){
		map.put(i,map.get(i)-1);
		if(map.get(i)==0)map.remove(i);
	}
	
	
	
	public void ascii(String s){
		for(char c:s.toCharArray()){
			System.out.print((c-'a')+"  ");
		}
		msg("");
	}
	
	public int flip(int i){
		if(i==0)return 1;
		else return 0;
	}
	
	public boolean[] primes(int n){
		boolean A[]=new boolean[n+1];
		for(int i=2;i<=n;i++){
			if(A[i]==false){
				for(int j=i+i;j<=n;j+=i){
					A[j]=true;
				}
			}
		}
		return A;
	}
	
	public void msg(String s){
		System.out.println(s);
	}
	
	public void msg1(String s){
		System.out.print(s);
	}
	
	public int[] kmpPre(String p){
		int pre[]=new int[p.length()];
		int l=0,r=1;
		while(r<p.length()){
			if(p.charAt(l)==p.charAt(r)){
				pre[r]=l+1;
				l++;r++;
			}else{
				if(l==0)r++;
				else l=pre[l-1];
			}
		}
		return pre;
	}
	
	public boolean isP(String s){
		int l=0,r=s.length()-1;
		while(l<r){
			if(s.charAt(l)!=s.charAt(r))return false;
			l++;r--;
		}
		return true;
	}
	
	public int find(int nums[],int x){//union find => find method
		if(nums[x]==x)return x;
		int root=find(nums,nums[x]);
		nums[x]=root;
		return root;
	}
	
 
	
	
	public int[] copy1(int A[]){
		int a[]=new int[A.length];
		for(int i=0;i<a.length;i++)a[i]=A[i];
		return a;
	}
	
	
	public void print1(int A[]){
		for(long i:A)System.out.print(i+"  ");
		System.out.println();
	}
	public void print2(int A[][]){
		for(int i=0;i<A.length;i++){
			for(int j=0;j<A[0].length;j++){
				System.out.print(A[i][j]+"   ");
			}System.out.println();
		}
	}
	
	public int min(int a,int b){
		return Math.min(a,b);
	}
	
	
	public int[][] matrixdp(int[][] grid) {
        if(grid.length==0)return new int[][]{};
        int res[][]=new int[grid.length][grid[0].length];
        for(int i=0;i<grid.length;i++){
            for(int j=0;j<grid[0].length;j++){
                res[i][j]=grid[i][j]+get(res,i-1,j)+get(res,i,j-1)-get(res,i-1,j-1);
            }
        }
        return res;
    }
    
    public int get(int grid[][],int i,int j){
        if(i<0||j<0||i>=grid.length||j>=grid[0].length)return 0;
        return grid[i][j];
    }
	
	public int[] suffixArray(String s){
		int n=s.length();
		Suffix A[]=new Suffix[n];
		
		for(int i=0;i<n;i++){
			A[i]=new Suffix(i,s.charAt(i)-'a',0);
		}
		
		for(int i=0;i<n;i++){
			if(i==n-1){
				A[i].next=-1;
			}else{
				A[i].next=A[i+1].rank;
			}
		}
		Arrays.sort(A);
		
		for(int len=4;len<A.length*2;len<<=1){
			int in[]=new int[A.length];
			int rank=0;
			int pre=A[0].rank;
			A[0].rank=rank;
			in[A[0].index]=0;
			for(int i=1;i<A.length;i++){//rank for the first two letter
				if(A[i].rank==pre&&A[i].next==A[i-1].next){
					pre=A[i].rank;
					A[i].rank=rank;
				}else{
					pre=A[i].rank;
					A[i].rank=++rank;
				}
				in[A[i].index]=i;
			}
			
			for(int i=0;i<A.length;i++){
				int next=A[i].index+len/2;
				if(next>=A.length){
					A[i].next=-1;
				}else{
					A[i].next=A[in[next]].rank;
				}
			}
			
			
			Arrays.sort(A);
		}
		
		
		int su[]=new int[A.length];
		for(int i=0;i<su.length;i++){
			su[i]=A[i].index;
		}
		return su;
	}
	
}
 
//suffix array Struct
class Suffix implements Comparable<Suffix>{
	int index;
	int rank;
	int next;
	public Suffix(int i,int rank,int next){
		this.index=i;
		this.rank=rank;
		this.next=next;
	}
	
	@Override
	public int compareTo(Suffix other) {
		if(this.rank==other.rank){
			return this.next-other.next;
		}
		return this.rank-other.rank;
	}
	
	public String toString(){
		return this.index+"   "+this.rank+"   "+this.next+"  ";
	}
}
 
 
 
class Wrapper implements Comparable<Wrapper>{
	int spf;int cnt;
	public Wrapper(int spf,int cnt){
		this.spf=spf;
		this.cnt=cnt;
	}
		
	@Override
	public int compareTo(Wrapper other) {
		return this.spf-other.spf;
	}
}
 
 
 
    class Node{//what the range would be for that particular node
		boolean state=false;
        int l=0,r=0;
		int ll=0,rr=0;
        public Node(boolean state){
            this.state=state;
        }
    }
	
	
	
	
	class Seg1{
			int A[];
			public Seg1(int A[]){
				this.A=A;
			}
			
			public void update(int left,int right,int val,int s,int e,int id){
				if(left<0||right<0||left>right)return;
				if(left==s&&right==e){
					
					A[id]+=val;
					return;
				}
				int mid=s+(e-s)/2; //[s,mid] [mid+1,e]
				
				if(left>=mid+1){
					update(left,right,val,mid+1,e,id*2+2);
				}else if(right<=mid){
					update(left,right,val,s,mid,id*2+1);
				}else{
					update(left,mid,val,s,mid,id*2+1);
					update(mid+1,right,val,mid+1,e,id*2+2);
				}
			}
			
			public int query(int i,int add,int s,int e,int id){
				
				if(s==e&&i==s){
					return A[id]+add;
				}
				
				int mid=s+(e-s)/2; //[s,mid] [mid+1,e]
				
				if(i>=mid+1){
					return query(i,A[id]+add,mid+1,e,id*2+2);
				}else{
					return query(i,A[id]+add,s,mid,id*2+1);
				}
			}
	}
 
 
	 class MaxFlow{
		
 
		  public static List<Edge>[] createGraph(int nodes) {
			List<Edge>[] graph = new List[nodes];
			for (int i = 0; i < nodes; i++)
			  graph[i] = new ArrayList<>();
			return graph;
		  }
 
		  public static void addEdge(List<Edge>[] graph, int s, int t, int cap) {
			graph[s].add(new Edge(t, graph[t].size(), cap));
			graph[t].add(new Edge(s, graph[s].size() - 1, 0));
		  }
 
		  static boolean dinicBfs(List<Edge>[] graph, int src, int dest, int[] dist) {
			Arrays.fill(dist, -1);
			dist[src] = 0;
			int[] Q = new int[graph.length];
			int sizeQ = 0;
			Q[sizeQ++] = src;
			for (int i = 0; i < sizeQ; i++) {
			  int u = Q[i];
			  for (Edge e : graph[u]) {
				if (dist[e.t] < 0 && e.f < e.cap) {
				  dist[e.t] = dist[u] + 1;
				  Q[sizeQ++] = e.t;
				}
			  }
			}
			return dist[dest] >= 0;
		  }
 
		  static int dinicDfs(List<Edge>[] graph, int[] ptr, int[] dist, int dest, int u, int f) {
			if (u == dest)
			  return f;
			for (; ptr[u] < graph[u].size(); ++ptr[u]) {
			  Edge e = graph[u].get(ptr[u]);
			  if (dist[e.t] == dist[u] + 1 && e.f < e.cap) {
				int df = dinicDfs(graph, ptr, dist, dest, e.t, Math.min(f, e.cap - e.f));
				if (df > 0) {
				  e.f += df;
				  graph[e.t].get(e.rev).f -= df;
				  return df;
				}
			  }
			}
			return 0;
		  }
 
		  public static int maxFlow(List<Edge>[] graph, int src, int dest) {
			int flow = 0;
			int[] dist = new int[graph.length];
			while (dinicBfs(graph, src, dest, dist)) {
			  int[] ptr = new int[graph.length];
			  while (true) {
				int df = dinicDfs(graph, ptr, dist, dest, src, Integer.MAX_VALUE);
				if (df == 0)
				  break;
				flow += df;
			  }
			}
			return flow;
		  }
		 
	 }
	 
	 	 class Edge {
			int t, rev, cap, f;
 
			public Edge(int t, int rev, int cap) {
			  this.t = t;
			  this.rev = rev;
			  this.cap = cap;
			}
		  }
		  
	   class Seg{
        int l,r;
        int min=Integer.MAX_VALUE;
        Seg left=null,right=null;
		int tree[];
        public Seg(int l,int r){
            this.l=l;
            this.r=r;
            if(l!=r){
                int mid=l+(r-l)/2;
                if(l<=mid)left=new Seg(l,mid);
                if(r>=mid+1)right=new Seg(mid+1,r);
                if(left!=null)min=Math.min(left.min,min);
                if(right!=null)min=Math.min(right.min,min);
            }else{
                min=tree[l];
            }
        }
        public int query(int s,int e){
            if(l==s&&r==e){
                return min;
            }
            int mid=l+(r-l)/2; //left :  to mid-1,
            if(e<=mid){
                return left.query(s,e);
            }
            else if(s>=mid+1){
                return right.query(s,e);
            }else{
                return Math.min(left.query(s,mid),right.query(mid+1,e));
            }
        }

        public void update(int index){
            if(l==r){
                min=tree[l];
                return;
            }
            int mid=l+(r-l)/2;
            if(index<=mid){
                left.update(index);
            }else{
                right.update(index);
            }
            this.min=Math.min(left.min,right.min);
        }
    }
	
	class Fenwick {
        int tree[];//1-index based
        int A[];
        int arr[];
        public Fenwick(int[] A) {
            this.A=A;
            arr=new int[A.length];
            tree=new int[A.length+1];
            int sum=0;
            for(int i=0;i<A.length;i++){
                update(i,A[i]);
            }
        }

        public void update(int i, int val) {
            arr[i]+=val;
            i++;
            while(i<tree.length){
                tree[i]+=val;
                i+=(i&-i);
            }
            
        }

        public int sumRange(int i, int j) {
            
            return pre(j+1)-pre(i);
        }

        public int pre(int i){
            int sum=0;
            while(i>0){
                sum+=tree[i];
                i-=(i&-i);
            }
            return sum;
        }
    }
	
    
		  
		  