#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
  ll a, b;
  cin >> a >> b;
  ll count = 0;
  ll n = 0;
  while (1) {
    n = a * n + b;
    count++;
    if (n == 0) {
      cout << count << endl;
      return 0;
    }
    if (count > 9999999) {
      cout << -1 << endl;
      return 0;
    }
  }
}