#include <bits/stdc++.h>

using namespace std;

#define rep(i, n) for(int i = 0; i < (int)n; ++i)
#define FOR(i, a, b) for(int i = a; i < (int)b; ++i)
#define rrep(i, n) for(int i = ((int)n - 1); i >= 0; --i)

using ll = long long;
using ld = long double;

const ll INF = 1e18;
const int Inf = 1e9;
const double EPS = 1e-9;
const int MOD = 1e9 + 7;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(0);
    ll a, b;
    cin >> a >> b;
    if ((a > 0 && b > 0) || (a < 0 && b < 0) || ((a != 0 && a != 1) && b == 0) || (a == 0 && b != 0)) {
        cout << -1 << endl;
        return 0;
    }
    ll n = 0;
    FOR (i, 1, 100000) {
        n = n * a + b;
        if (n == 0) {
            cout << i << endl;
            return 0;
        }
    }
    
    return 0;
}