// I SELL YOU...! 
#include<iostream>
#include<vector>
#include<algorithm>
#include<functional>
#include<queue>
#include<chrono>
#include<iomanip>
#include<map>
#include<set>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
using TP = tuple<ll,ll,ll>;
void init_io(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(18);
}
signed main(){
  init_io();
  ll a,b;
  cin >> a >> b;
  if(a==0){
    if(b==0) cout << 1<<endl;
    else cout <<-1<<endl;
  }else if(abs(a)==1){
    if(b==0) cout << 1<<endl;
    else cout <<-1<<endl;
  }else{
    ll n=0;
    for(int i=1;i<1e7;i++){
      n = a*n+b;
      if(n==0){
        cout << i<<endl;
        break;
      }else if(abs(n)>1e18){
        cout << -1<<endl;
        break;
      }
    }
  }
}