#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  ull n, b;
  cin >> n >> b;
  n %= b;
  rep(i, b) {
    if (n * i % b == 1 % b) {
      cout << i << '\n';
      return 0;
    }
  }
  cout << "NaN" << '\n';
  return 0;
}