a =input()
b =input()
hanbetu=1

if a.isdigit()==True:
	hanbetu=1
else:
	hanbetu=0

if b.isdigit()==True:
	hanbetu=1
else:
	hanbetu=0


if hanbetu ==1:
	if int(a) <=12345 and int(a) >=0:
		hanbetu=0
	
	if int(b) >=12345 and int(b) >=0:
		hanbetu=0
	else:
		hanbetu=1

if hanbetu==1:
	print("OK")
else:
	print("NG")