http://codeforces.com/contest/371/problem/B
1 #include <cstdio> 2 #include <iostream> 3 #include <cstring> 4 #include <algorithm> 5 #define ll int 6 using namespace std; 7 8 ll a,b; 9 int ans=0; 10 int m1,m2; 11 int check(ll x) 12 { 13 while(x) 14 { 15 if(x%2==0) 16 x/=2; 17 else if(x%3==0) 18 x/=3; 19 else if(x%5==0) 20 x/=5; 21 else 22 { 23 break; 24 } 25 ans++; 26 } 27 return x; 28 } 29 30 ll gcd(ll c,ll d) 31 { 32 return d==0?c:gcd(d,c%d); 33 } 34 35 int main() 36 { 37 cin>>a>>b; 38 if(a==b) 39 { 40 printf("0 "); 41 return 0; 42 } 43 int s=gcd(a,b); 44 a/=s; 45 b/=s; 46 if(check(a)==check(b)) 47 { 48 printf("%d ",ans); 49 } 50 else printf("-1 "); 51 return 0; 52 }