#include<bits/stdc++.h>
using namespace std;
int main()
{
  unsigned long long N; cin >> N;
  unsigned int B; cin >> B;
  N %= B;
  unsigned int one = 1 % B;
  for( unsigned int i = 0 ; i < B ; i++ ){
    if( N * i % B == one ){
      cout << i << "\n";
      return 0;
    }
  }
  cout << "NaN\n";
}