cf B. Fox Dividing Cheese

http://codeforces.com/contest/371/problem/B

 #include <cstdio>
 #include <iostream>
 #include <cstring>
 #include <algorithm>
 #define ll int
 using namespace std;

 ll a,b;
 int ans=;
 int m1,m2;
 int check(ll x)
 {
     while(x)
     {
         if(x%==)
         x/=;
         else if(x%==)
         x/=;
         else if(x%==)
         x/=;
         else
         {
            break;
         }
         ans++;
     }
     return x;
 }

 ll gcd(ll c,ll d)
 {
     return d==?c:gcd(d,c%d);
 }

 int main()
 {
     cin>>a>>b;
     if(a==b)
     {
         printf("0\n");
         return ;
     }
     int s=gcd(a,b);
     a/=s;
     b/=s;
     if(check(a)==check(b))
     {
         printf("%d\n",ans);
     }
     else printf("-1\n");
     return ;
 }