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
import java.io.*;
import java.util.*;



import java.math.*;
import java.lang.*;
 
import static java.lang.Math.*;
 
public class Cf131 implements Runnable 
{
    static class InputReader 
    {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;
        private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 
        public InputReader(InputStream stream) 
        {
            this.stream = stream;
        }
        
        public int read()
        {
            if (numChars==-1) 
                throw new InputMismatchException();
            
            if (curChar >= numChars) 
            {
                curChar = 0;
                try
                {
                    numChars = stream.read(buf);
                }
                catch (IOException e)
                {
                    throw new InputMismatchException();
                }
                
                if(numChars <= 0)               
                    return -1;
            }
            return buf[curChar++];
        }
     
        public String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }    
            return str;
        }
        public int nextInt() 
        {
            int c = read();
            
            while(isSpaceChar(c)) 
                c = read();
        
            int sgn = 1;
        
            if (c == '-') 
            {
                sgn = -1;
                c = read();
            }
            
            int res = 0;
            do
            {
                if(c<'0'||c>'9') 
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c)); 
        
            return res * sgn;
        }
        
        public long nextLong() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            long res = 0;
            
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }    
            while (!isSpaceChar(c));
                return res * sgn;
        }
        
        public double nextDouble() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') 
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') 
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c))
                {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
    
        public String readString() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = read();
            } 
            while (!isSpaceChar(c));
            
            return res.toString();
        }
     
        public boolean isSpaceChar(int c) 
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
     
        public String next()
        {
            return readString();
        }
        
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
    public static void main(String args[]) throws Exception 
    {
        new Thread(null, new Cf131(),"Main",1<<27).start();
    }
    
    static class Pair{
		int nod;
        int ucn;
        int siz;
		
		Pair(int nod,int ucn,int siz){
			this.nod=nod;
            this.ucn=ucn;
            this.siz = siz;
		}
		
	public static Comparator<Pair> wc = new Comparator<Pair>(){
		public int compare(Pair e1,Pair e2){
            int c1 = e1.ucn - e1.siz;
            int c2 = e2.ucn - e2.siz;
            //reverse order
			if (c1 < c2) 
                return 1;  // 1 for swaping.
            else if (c1 > c2) 
                return -1; 
            else{
                if(e1.siz>e2.siz)
                    return 1;
                else
                    return -1;
            } 
		}
	};	
	}

    public static int gcd(int a,int b){
        if(b==0)return a;
        else return gcd(b,a%b);
    }
//// iterative BFS
    public static void bfs(int s,ArrayList<Integer>[] a,int[] dist,boolean[] b,PrintWriter w){
        b[s]=true;
        
        Queue<Integer> q = new LinkedList<>();
        q.add(s);
        while(q.size()!=0){
            int i=q.poll();
        //    w.println(" #"+i+"# ");
            Iterator<Integer> it =a[i].listIterator();
            int z=0;
            while(it.hasNext()){
                z=it.next();
                
                if(!b[z]){
                //    w.println("* "+z+" *");
                    b[z]=true;
                  dist[z] = dist[i]+1;
                //    x.add(z);
                //    w.println("@ "+x.get(x.size()-1)+" @");
                    q.add(z);
                }
            }   
        
        }
    }
////recursive BFS
    public static int bfsr(int s,ArrayList<Integer>[] a,int[] dist,boolean[] b,int[] pre){
        b[s]=true;
        int p = 0;
        int t = a[s].size();
        for(int i=0;i<t;i++){
            int x = a[s].get(i);
            if(!b[x]){
                dist[x] = dist[s] + 1;
                p+= (bfsr(x,a,dist,b,pre)+1);
            }
        }
        pre[s] = p;
        return p;
    }



  


//////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////
  
 
    public void run()
    {
        InputReader sc = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);
        
        //int t= sc.nextInt();
        //while(t-->0){

            int a = sc.nextInt();
            int b = sc.nextInt();
            
            int g = gcd(a,b);
            a = a/g;
            b = b/g;
            
            long ans = 0;
            while(a>1){
                if(a%5==0)a = a/5;
                else if(a%3==0)a = a/3;
                else if(a%2==0)a = a/2;
                else{ans = -1;break;}
                ans++;
            }
            while(ans!=-1 && b>1){
                if(b%5==0)b = b/5;
                else if(b%3==0)b = b/3;
                else if(b%2==0)b = b/2;
                else{ans = -1;break;}
                ans++;
            }
            w.print(ans);
            
            
        //}
        w.flush();
        w.close();

        
    }

}