from collections import defaultdict


def main():
    A = input()
    B = input()
    
    if A.isnumeric() and B.isnumeric():
        if 0 <= int(A) <= 12345 and 0 <= int(B) <= 12345:
            print("OK")
            return
    print("NG")


if __name__ == '__main__':
    main()