#include <bits/stdc++.h>
using namespace std;
#pragma GCC target("avx2")
#pragma GCC optimization("unroll-loops")
#pragma GCC optimize("O2")
constexpr int dx[] = {-1, 0, 1, 0, 1, 1, -1, -1};
constexpr int dy[] = {0, -1, 0, 1, 1, -1, 1, -1};
constexpr long long INF = 1999999999999999997;
constexpr int inf = INT_MAX;
constexpr int MAXSIZE = int(1e6) + 5;
constexpr auto PI = 3.14159265358979323846L;
constexpr auto oo = numeric_limits<int>::max() / 2 - 2;
constexpr auto eps = 1e-6;
constexpr auto mod = 1000000007;
constexpr auto MOD = 1000000007;
constexpr auto MOD9 = 1000000009;
constexpr auto maxn = 100006;
void fastio() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
int v[2][3];
int main() {
  fastio();
  int a[2];
  cin >> a[0] >> a[1];
  int b[] = {2, 3, 5};
  for (int i = 0; i < 2; i++) {
    for (int j = 0; j < 3; j++) {
      while (a[i] % b[j] == 0) {
        a[i] /= b[j];
        v[i][j]++;
      }
    }
  }
  if (a[0] != a[1]) {
    cout << "-1";
    return 0;
  }
  int ans = 0;
  for (int i = 0; i < 3; i++) {
    ans += (abs(v[1][i] - v[0][i]));
  }
  cout << ans;
}
