# 20240911
def f1(x):  # 包括大小写字母.数字.其它符号,以上四种至少三种
    a, b, c, other = 0, 0, 0, 0
    for i in x:
        if ord('A') <= ord(i) <= ord('Z'):
            a = 1
        elif ord('a') <= ord(i) <= ord('z'):
            b = 1
        elif ord('0') <= ord(i) <= ord('9'):
            c = 1
        else:
            other = 1
    if a + b + c + other < 3:
        return False
    return True


def f2(x):  # 不能有长度大于2的包含公共元素的子串重复 (注:其他符号不含空格或换行)
    for i in range(len(x)):
        if x[i : i + 3] in x[i+3:]:
            return False
    return True

while True:
    try:

        s = input()
       # print(f1(s), f2(s))
        if len(s) > 8 and f1(s) and f2(s):
            print("OK")
        else:
            print("NG")
    except:
        break