def check(s):
    x=[]
    a,b,ct,d=0,0,0,0
    if len(s) <= 8:
        return 0
    else:
        for i in s:
            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"):
                ct=1
            else:
                d=1
        if a+b+ct+d < 3:
            return 0
        else:
            for i in range(len(s)-2):
                x.append(s[i:i+3])
            if len(set(x)) < len(x):
                return 0
            else:
                return 1
while True:
    try:
        if check(input()):
            print("OK")
        else:
            print("NG")
    except:
        break