a,b = input(),input()
if a.isdigit() and b.isdigit():
    if str(int(a))==a and str(int(b))==b:
        if int(a)<=12345 and int(b)<=12345:
            print("OK")
        else:
            print("NG")
    else:
        print("NG")
else:
    print("NG")