#include <bits/stdc++.h>
using namespace std;

int main(){
    unsigned long long n, b;
    cin >> n >> b;
    if(b == 1){
        cout << "0\n";
        return 0;
    }
    const unsigned int d = n % b;
    unsigned int v = 0;
    for(unsigned int i = 1; i < b; i++){
        v += d;
        if(v >= b) v -= b;
        if(v == 1){
            cout << i << '\n';
            return 0;
        }
    }
    cout << "NaN\n";
}