//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int siz(string s){
  return (int)s.size();
}

int main(){
  ll A, B; cin >> A >> B;

  if(B == 0){
    printl(1);

    return 0;
  }

  ll X1 = B;
  ll X2 = A*X1 + B;

  if(X2 == 0){
    printl(2);

    return 0;
  }
  
  if(X2 > X1){
    if(X2 < 0){
      for(int i = 3; ; i++){
        ll X = A*X2 + B;

        if(X == 0){
          printl(i);

          return 0;
        }else if(X > 0){
          printl(-1);

          return 0;
        }

        X2 = X;
      }
    }
  }else if(X2 < X1){
    if(X2 > 0){
      for(int i = 3; ; i++){
        int X = A*X2 + B;

        if(X == 0){
          printl(i);

          return 0;
        }else if(X < 0){
          printl(-1);

          return 0;
        }

        X2 = X;
      }
    }
  }

  printl(-1);

  return 0;
}