#include <bits/stdc++.h>

using namespace std;

int main() {

long long n,m,judge=0,tt=0;

while(cin>>n>>m){

if(m<=0){

    cout<<"Go Kevin!!"<<endl;

    continue;

}

for(long long i=1;tt<n;i++){

    tt = i + (i-1+0)*i/2*m;

    if(tt==n){

        judge=1;

        break;

    }

}

if(judge)

    cout<<"Go Kevin!!"<<endl;

else

    cout<<"No Stop!!"<<endl;

judge = 0;

tt = 0;

}

}