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.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;

public class S {
	
	static private long ans;
	static private long count1;
	static private long count2;
	static private long tmp;
	
	private static int[][] arr;
	private static int n;
	
	private static long[] larr;
	
	static class Reader {
		
		static BufferedReader reader;
		static StringTokenizer tokenizer;
		
		static void init(InputStream input) {
			reader = new BufferedReader(new InputStreamReader(input));
			tokenizer = new StringTokenizer("");
		}
		
		static String next() throws IOException {
			while(!tokenizer.hasMoreTokens()) {
				tokenizer = new StringTokenizer(reader.readLine());
			}
			return tokenizer.nextToken();
		}
		
		static int nextInt() throws IOException {
			return Integer.parseInt(next());
		}
		
		static long nextLong() throws IOException {
			return Long.parseLong(next());
		}
		
	}

	
	static int[] merge(int[] a, int[] b) {
		int m = a.length;
		int n = b.length;
		int [] c = new int[n+m];
		
		int j=0, k=0;
		while(j+k<m+n) {
			if(j>=m) {
				c[j+k] = b[k];
				k++;
			}
			else if(k>=n) {
				c[j+k] = a[j];
				j++;
			}
			else {
				if(a[j]<b[k]) {
					c[j+k] = a[j];
					j++;
				}
				else if(a[j]==b[k]) {
					if(a[j]<b[k]) {
						c[j+k] = a[j];
						j++;
					}
					else {
						c[j+k] = b[k];
						k++;
					}
				}
				else {
					c[j+k] = b[k];
					k++;
				}
			}
		}
		return c;
	}
	
	static int[] Msort(int[] unsorted){
		int l = unsorted.length;
		
		if(l<=1) {
			return unsorted;
		}
		
		else {
			int[] Msorted = new int[l];
			int[] m1 = new int[l/2];
			int[] m2 = new int[l-(l/2)];
			
			for(int i=0; i<l; i++) {
				if(i<l/2) {
					m1[i] = unsorted[i];
				}
				else {
					m2[i-(l/2)] = unsorted[i];
				}
			}
			
			Msorted = merge(Msort(m1), Msort(m2));		
			
			return Msorted;
		}
		
	}
	
	static long[] merge(long[] a, long[] b) {
		int m = a.length;
		int n = b.length;
		long [] c = new long[n+m];
		
		int j=0, k=0;
		while(j+k<m+n) {
			if(j>=m) {
				c[j+k] = b[k];
				k++;
			}
			else if(k>=n) {
				c[j+k] = a[j];
				j++;
			}
			else {
				if(a[j]<b[k]) {
					c[j+k] = a[j];
					j++;
				}
				else if(a[j]==b[k]) {
					if(a[j]<b[k]) {
						c[j+k] = a[j];
						j++;
					}
					else {
						c[j+k] = b[k];
						k++;
					}
				}
				else {
					c[j+k] = b[k];
					k++;
				}
			}
		}
		return c;
	}
	
	static long[] Msort(long[] unsorted){
		int l = unsorted.length;
		
		if(l<=1) {
			return unsorted;
		}
		
		else {
			long[] Msorted = new long[l];
			long[] m1 = new long[l/2];
			long[] m2 = new long[l-(l/2)];
			
			for(int i=0; i<l; i++) {
				if(i<l/2) {
					m1[i] = unsorted[i];
				}
				else {
					m2[i-(l/2)] = unsorted[i];
				}
			}
			
			Msorted = merge(Msort(m1), Msort(m2));		
			
			return Msorted;
		}
		
	}

	
	static int[][] merge_x(int[][] a, int[][] b) {
		int m = a.length;
		int n = b.length;
		int [][] c = new int[n+m][2];
		
		int j=0, k=0;
		while(j+k<m+n) {
			if(j>=m) {
				c[j+k][0] = b[k][0];
				c[j+k][1] = b[k][1];
				k++;
			}
			else if(k>=n) {
				c[j+k][0] = a[j][0];
				c[j+k][1] = a[j][1];
				j++;
			}
			else {
				if(a[j][0]<b[k][0]) {
					c[j+k][0] = a[j][0];
					c[j+k][1] = a[j][1];
					j++;
				}
				else if(a[j][0]==b[k][0]) {
					if(a[j][1]<b[k][1]) {
						c[j+k][0] = a[j][0];
						c[j+k][1] = a[j][1];
						j++;
					}
					else {
						c[j+k][0] = b[k][0];
						c[j+k][1] = b[k][1];
						k++;
					}
				}
				else {
					c[j+k][0] = b[k][0];
					c[j+k][1] = b[k][1];
					k++;
				}
			}
		}
		return c;
	}
	
	static int[][] Msort_x(int[][] unsorted){
		int l = unsorted.length;
		
		if(l<=1) {
			return unsorted;
		}
		
		else {
			int[][] Msorted = new int[l][2];
			int[][] m1 = new int[l/2][2];
			int[][] m2 = new int[l-(l/2)][2];
			
			for(int i=0; i<l; i++) {
				if(i<l/2) {
					m1[i][0] = unsorted[i][0];
					m1[i][1] = unsorted[i][1];
				}
				else {
					m2[i-(l/2)][0] = unsorted[i][0];
					m2[i-(l/2)][1] = unsorted[i][1];
				}
			}
			
			Msorted = merge_x(Msort_x(m1), Msort_x(m2));
			
			return Msorted;
		}
		
	}
	
	static int[][] merge_y(int[][] a, int[][] b) {
		int m = a.length;
		int n = b.length;
		int [][] c = new int[n+m][2];
		
		int j=0, k=0;
		while(j+k<m+n) {
			if(j>=m) {
				c[j+k][0] = b[k][0];
				c[j+k][1] = b[k][1];
				k++;
			}
			else if(k>=n) {
				c[j+k][0] = a[j][0];
				c[j+k][1] = a[j][1];
				j++;
			}
			else {
				if(a[j][1]<b[k][1]) {
					c[j+k][0] = a[j][0];
					c[j+k][1] = a[j][1];
					j++;
				}
				else if(a[j][1]==b[k][1]) {
					if(a[j][0]<b[k][0]) {
						c[j+k][0] = a[j][0];
						c[j+k][1] = a[j][1];
						j++;
					}
					else {
						c[j+k][0] = b[k][0];
						c[j+k][1] = b[k][1];
						k++;
					}
				}
				else {
					c[j+k][0] = b[k][0];
					c[j+k][1] = b[k][1];
					k++;
				}
			}
		}
		return c;
	}
	
	static int[][] Msort_y(int[][] unsorted){
		int l = unsorted.length;
		
		if(l<=1) {
			return unsorted;
		}
		
		else {
			int[][] Msorted = new int[l][2];
			int[][] m1 = new int[l/2][2];
			int[][] m2 = new int[l-(l/2)][2];
			
			for(int i=0; i<l; i++) {
				if(i<l/2) {
					m1[i][0] = unsorted[i][0];
					m1[i][1] = unsorted[i][1];
				}
				else {
					m2[i-(l/2)][0] = unsorted[i][0];
					m2[i-(l/2)][1] = unsorted[i][1];
				}
			}
			
			Msorted = merge_y(Msort_y(m1), Msort_y(m2));
			
			return Msorted;
		}
		
	}
	
	static int[][] merge_3(int[][] a, int[][] b) {
		int m = a.length;
		int n = b.length;
		int [][] c = new int[n+m][3];
		
		int j=0, k=0;
		while(j+k<m+n) {
			if(j>=m) {
				c[j+k][0] = b[k][0];
				c[j+k][1] = b[k][1];
				c[j+k][2] = b[k][2];
				k++;
			}
			else if(k>=n) {
				c[j+k][0] = a[j][0];
				c[j+k][1] = a[j][1];
				c[j+k][2] = a[j][2];
				j++;
			}
			else {
				if(a[j][0]<b[k][0]) {
					c[j+k][0] = a[j][0];
					c[j+k][1] = a[j][1];
					c[j+k][2] = a[j][2];
					j++;
				}
				else if(a[j][0]==b[k][0] && a[j][1]<b[k][1]) {
					c[j+k][0] = a[j][0];
					c[j+k][1] = a[j][1];
					c[j+k][2] = a[j][2];
					j++;
				}
				else {
					c[j+k][0] = b[k][0];
					c[j+k][1] = b[k][1];
					c[j+k][2] = b[k][2];
					k++;
				}
			}
		}
		return c;
	}
	
	static int[][] Msort_3(int[][] unsorted){
		int l = unsorted.length;
		
		if(l<=1) {
			return unsorted;
		}
		
		else {
			int[][] Msorted = new int[l][3];
			int[][] m1 = new int[l/2][3];
			int[][] m2 = new int[l-(l/2)][3];
			
			for(int i=0; i<l; i++) {
				if(i<l/2) {
					m1[i][0] = unsorted[i][0];
					m1[i][1] = unsorted[i][1];
					m1[i][2] = unsorted[i][2];
				}
				else {
					m2[i-(l/2)][0] = unsorted[i][0];
					m2[i-(l/2)][1] = unsorted[i][1];
					m2[i-(l/2)][2] = unsorted[i][2];
				}
			}
			
			Msorted = merge_3(Msort_3(m1), Msort_3(m2));
			
			return Msorted;
		}
		
	}

	
	public static void print2dArray(int [][] arr) {
		for(int i=0; i<arr.length; i++) {
			System.out.println(arr[i][0]+" "+arr[i][1]+" ");
		}
	}
	
	public static void solve_x() {
		
		int i=1;
		count1=1;
		
		while(i<n) {
			
			if(arr[i][0]==arr[i-1][0]) {
				count1++;
			}
			else {
				ans+=(count1*(count1-1))/2;
				count1=1;
			}
			
			i++;
			
		}

		
		ans+=(count1*(count1-1))/2;
		
	}
	
	public static void solve_y() {

		int i=1;
		count1=1;
		count2=1;
		
		while(i<n) {

			//System.out.println(count1);
				
			boolean b1 = arr[i][1]==arr[i-1][1]; 
			boolean b2 = arr[i][0]==arr[i-1][0];
						
			if(b1&&b2) {
				count1++;
				count2++;
			}
			else if(b1) {
				count1++;
				ans-=(count2*(count2-1))/2;
				
				//System.out.println("ans: "+ans+" count1: "+count1);
				count2=1;
			}
			else {
				ans+=(count1*(count1-1))/2;
				//System.out.println("ans: "+ans);
				ans-=(count2*(count2-1))/2;
				//System.out.println("ans: "+ans);
				count1=1;
				count2=1;
			}
			
			i++;
			
		}
		ans-=(count2*(count2-1))/2;
		ans+=(count1*(count1-1))/2;
		
	}
	
    static boolean binarySearch(int arr[], int x, int y) 
    { 
        int l = 0, r = arr.length - 1; 
        while (l <= r) { 
            int m = l + (r - l) / 2; 
  
            // If x greater, ignore left half 
            if (arr[m] < x) 
                l = m + 1; 
  
            // If x is smaller, ignore right half 
            else if(arr[m] > y)
                r = m - 1; 
            
            else {
            	return true;
            }
        } 
  
        // if we reach here, then element was 
        // not present 
        return false; 
    } 
    
    static int gcd(int a, int b) 
    { 
        if (a == 0) 
            return b; 
        return gcd(b % a, a); 
    } 
  
    // Function to find gcd of array of 
    // numbers 
    static int findGCD(int arr[]) 
    { 
        int result = 0; 
        for (int element: arr){ 
            result = gcd(result, element); 
  
            if(result == 1) 
            { 
               return 1; 
            } 
        } 
  
        return result; 
    }
	
	public static void main(String[] args) throws IOException {
		
		tmp = 0;
		count1 = 0;
		count2 = 0;
		
		ans = 0;
		
		Reader.init(System.in);
		
		OutputStream out = new BufferedOutputStream(System.out);
		
		int a = Reader.nextInt();
		int b = Reader.nextInt();
		
		int g = gcd(a,b);
		
		int a1 = a/g;
		int b1 = b/g;
		ans = 0;
		boolean possible = check(a1) && check(b1);
		
	//	System.out.println(ans);
	//	out.write(Long.toString(ans).getBytes());
		
		if(!possible) {
			System.out.println(-1);
		}
		else {
			out.write(Long.toString(ans).getBytes());
		}
		out.close();
		
		
	

	}

	private static boolean check(int x) {
		// TODO Auto-generated method stub
		
		while(x%2==0) {
			ans++;
			x/=2;
		}
		
		while(x%3==0) {
			ans++;
			x/=3;
		}
		
		while(x%5==0) {
			ans++;
			x/=5;
		}		
		
		if(x==1) {
			return true;
		}
		else {
			return false;
		}
	}

}

// 3 4 6 5 15 1 1 9 12 13
