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

bool lzero(string s) {
    return s.size() > 1 && s[0] == '0';
}

bool isnum(string s) {
    for (char c : s) if (c < '0' || '9' < c) return false;
    return true;
}

int main() {
    string a, b;
    cin>>a>>b;
    if (lzero(a)||lzero(b)||!isnum(a)||!isnum(b)||stoi(a)>12345||stoi(b)>12345) puts("NG");
    else puts("OK");
    return 0;
}