#include <bits/stdc++.h>

using namespace std;

void fast_io() {
	ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
}

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