#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ull=unsigned long long;
int main()
{   
    ull n;
    int b;
    cin>>n>>b;
    n%=b;
    for(ull i=1;i<=b;i++){
        if(i*n%b==1%b){
            cout<<i<<endl;
            return 0;
        }
    }
    cout<<"NaN"<<endl;
    
    return 0;
}