#include <iostream>
#include <string>
#include <stdexcept>
using namespace std;

int main(void) {
    string a, b;
    cin >> a >> b;
    int ai, bi;
    try{
        ai = stoi(a);
        bi = stoi(b);
    }
    catch(const invalid_argument& e) {
        cout << "NG" << endl;
        return 0;
    }
    catch(const out_of_range& e) {
        cout << "NG" << endl;
        return 0;
    }
    if (ai>12345 || ai<0 || bi>12345 || bi<0) {
        cout << "NG" << endl;
    }
    else {
        cout << "OK" << endl;
    }


    return 0;
}