#include <bits/stdc++.h>

using namespace std;

int main() {
    unsigned long long N;
    int B;
    cin >> N >> B;
    if (B == 1) {
        cout << 0 << endl;
        return 0;
    }
    N %= B;
    for (int i = 0; i < B; i++) {
        if (N * i % B == 1) {
            cout << i << endl;
            return 0;
        }
    }
    cout << "NaN" << endl;
    return 0;
}