题解 | #密码验证合格程序#

import sys

# for line in sys.stdin:
#    a = line.split()
#   print(int(a[0]) + int(a[1]))


s = input()
s = list(s)

# 长度判断合格与否
def lenisok(s):
    if len(s) > 8:
        return True


# 判断元素的种类大于三种
def classisok(s):
    caps = 0
    lows = 0
    numbers = 0
    others = 0
    for x in s:
        if x >= "A" and x <= "Z":
            caps = 1
        elif x >= "a" and x <= "z":
            lows = 1
        elif x >= "0" and x <= "9":
            numbers = 1
        else:
            others = 1
    sum = caps + lows + numbers + others
    return sum

#验证字符串中有没有2个以上的重复的字符串，先将大于2个字符的字符串遍历出来，然后对遍历出来的元素组成的列表做一##个去重前后的对比
def f(s):
    n=len(s)
    L=[]
    for length in range(3,n+1):
        for index in range(0,n-length):
            L.append(s[index:index+length])
    #print(L)
    m1 = len(L)
        #print(set(L))
    L2=[]
    for x in L:
        x="".join(x)
        L2.append(x)
    m2 =len(set(L2))
    if m1>m2:
        return False
    else:
        return True



if classisok(s) >= 3 and lenisok(s) and f(s):
    print("OK")
else:
    print("NG")