#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

ll calc(ll d) {
  return (ll)((-1 + sqrt(1 + 4*d)) / 2.0);
}

int main() {
    int cnt = 0;
    for(ll i = 900000000; i >= 890000000; i--){
         ll d = i * i + i - 1; //cin >> d;
        ll t = calc(d);
        //cout << t << endl;
        //cout << t*t + t << endl;
        //t++;
        //cout << t*t + t << endl;
        if(t*t + t > d){
            // cout << "NG!!" << endl;
            // cout <<d << ' ' <<  i  << ' ' << t - 1<< endl;
            //cout << d << endl;
            cnt++;
        }
        else{
            // cout << "OK" << endl;
            // cout << d <<  ' ' << i << endl;
        }
        if(cnt == 100000){
             cout << "OK" << endl;
            break;
        }
    }
  return 0;
}