#include <bits/stdc++.h>

using namespace std;

#define FOR(i, j, k) for(int i = j; i < k; ++i)
#define rep(i, j) FOR(i, 0, j)
#define repr(i, j) for(int i = j; i >= 0; --i)
#define INF (1 << 30)
#define MOD 1e9 + 7

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int main() {
	string a, b;
	cin >> a >> b;
	if(a[0] != '0' && b[0] != '0') {
		rep(i, a.size()) {
			if(a[i] < '0' || a[i] > '9') {
				printf("NG\n");
				return 0;
			} 
		}
		if(5 > a.size()) printf("OK\n");
		else if("12345" >= a) printf("OK\n");
		else printf("NG\n");
		rep(i, b.size()) {
			if(b[i] < '0' || b[i] > '9') {
				printf("NG\n");
				return 0;
			} 
		}
		if(5 > b.size()) printf("OK\n");
		else if("12345" >= b) printf("OK\n");
		else printf("NG\n");
	}
	else printf("NG\n");
	return 0;
}