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