import math

ng_flg = 1

a = input()
b = input()

# 入力チェック
if a.find("0") != 0 and b.find("0") != 0:
    if a.isdigit() and b.isdigit():
        n = int(a)
        m = int(b)
        if  0<=n<=12345 and 0<=m<=12345:
            ng_flg = 0
            print("OK")
if ng_flg == 1:
    print("NG")