#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

bool lz(const string &s){
    if(s.size() == 1){
        return false;
    }
    return s[0] == '0';
}

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    string A, B;
    std::cin >> A >> B;
    
    if(all_of(A.begin(), A.end(), [](char c){return isdigit(c);}) &&
       all_of(B.begin(), B.end(), [](char c){return isdigit(c);}) &&
       !lz(A) && !lz(B) &&
       stoi(A) <= 12345 && stoi(B) <= 12345){
        std::cout << "OK" << std::endl;
    }else{
        std::cout << "NG" << std::endl;
    }
}