#include <bits/stdc++.h>
using namespace std;
const int dx[] = {-1, 0, 0, 1};
const int dy[] = {0, -1, 1, 0};
int cnt[2][10];
int main() {
  int a, b;
  cin >> a >> b;
  while (a % 2 == 0 || a % 3 == 0 || a % 5 == 0) {
    if (a % 2 == 0) {
      a /= 2;
      cnt[0][2]++;
    }
    if (a % 3 == 0) {
      a /= 3;
      cnt[0][3]++;
    }
    if (a % 5 == 0) {
      a /= 5;
      cnt[0][5]++;
    }
  }
  while (b % 2 == 0 || b % 3 == 0 || b % 5 == 0) {
    if (b % 2 == 0) {
      b /= 2;
      cnt[1][2]++;
    }
    if (b % 3 == 0) {
      b /= 3;
      cnt[1][3]++;
    }
    if (b % 5 == 0) {
      b /= 5;
      cnt[1][5]++;
    }
  }
  if (a != b)
    puts("-1");
  else {
    cout << abs(cnt[0][2] - cnt[1][2]) + abs(cnt[0][3] - cnt[1][3]) +
                abs(cnt[0][5] - cnt[1][5])
         << endl;
  }
  return 0;
}
