#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int a, b;
  int a2 = 0, a3 = 0, a5 = 0;
  int b2 = 0, b3 = 0, b5 = 0;
  cin >> a >> b;
  while (a % 2 == 0) a /= 2, a2++;
  while (a % 3 == 0) a /= 3, a3++;
  while (a % 5 == 0) a /= 5, a5++;
  while (b % 2 == 0) b /= 2, b2++;
  while (b % 3 == 0) b /= 3, b3++;
  while (b % 5 == 0) b /= 5, b5++;
  if (a != b)
    cout << -1 << "\n";
  else
    cout << abs(a2 - b2) + abs(a3 - b3) + abs(a5 - b5) << "\n";
  return 0;
}
