#include <bits/stdc++.h>
#define rep(i,n) for (int (i) = 0; (i) < (n); i++)
#define ll long long
using namespace std;
 
int main() {
  ll A = 0,B = 0,N = 0,ans = 0;
  cin >> A >> B;
  if(A > 0 && B > 0){
    cout << "-1" << endl;
    return 0;
  }
  if(B == 0){
    cout << "1" << endl;
    return 0;
  }
  rep(i,10000){
    N = A * N + B;
    ans++;
    if(N == 0){
      cout << ans << endl;
      return 0;
    }
  }
  cout << "-1" << endl;
  return 0;
}