a=input()
b=input()
if a.isdigit()==0 or b.isdigit()==0:print("NG")
elif a!="0" and a[0]=="0" or b!="0" and b[0]=="0":print("NG")
else:
	A=int(a)
	B=int(b)
	if A>12345 or B>12345:print("NG")
	else:print("OK")