low = set([chr(i) for i in range(67, 91)]) cap = set([chr(i) for i in range(97, 123)]) num = set([str(i) for i in range(10)]) while True: try: string = input().strip() n = len(string) s = string if n < 9: print('NG') continue

    string = set(list(string))
    res = 0
    if low & string:
        res += 1
    if cap & string:
        res += 1
    if num & string:
        res += 1
    if not (num & string and cap & string and low & string):
        res += 1
    li = []
    for i in range(n - 3):
        li.append(s[i:i + 3])
    n1 = len(set(li))
    n2 = len(li)
    if n2 - n1 >= 1:
        print('NG')
        continue

    if res < 3:
        print('NG')
    else:
        print('OK')

except (EOFError, KeyboardInterrupt):
    break