a=input()
b=input()

if a.isnumeric()==False or b.isnumeric()==False:
    print("NG")
elif (a!="0" and a[0]=="0")  or (b!="0" and b[0]=="0") :
        print("NG")
elif int(a)>0 and int(b)>12345:
    print("NG")
else:
    print("OK")