#include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;

int main() {
	string A, B;
	cin >> A >> B;

	bool b = true;
	if (A.size() < 1 || A.size() > 5) b = false;
	if (B.size() < 1 || B.size() > 5) b = false;

	if (b) {
		int f = 0;
		for (int i = 0; i < A.size(); i++) {
			if (A.at(i) < '0' || A.at(i) > '9') {
				b = false;
				break;
			}
			else {
				if (A.at(i) != '0') {
					f = 1;
				}
				else {
					if (!f && A.size() != 1) {
						b = false;
						break;
					}
				}
			}
		}
	}

	if (b) {
		for (int i = 0; i < B.size(); i++) {
			int f = 0;

			if (B.at(i) < '0' || B.at(i) > '9') {
				b = false;
				break;
			}
			else {
				if (B.at(i) != '0') {
					f = 1;
				}
				else {
					if (!f && B.size() != 1) {
						b = false;
						break;
					}
				}
			}
		}
	}

	if (b) {
		int n, m;
		n = stoi(A);
		m = stoi(B);
		if (n > 12345 || m > 12345) b = false;
	}

	cout << (b ? "OK" : "NG") << endl;
}