num = int(input("enter a year "))
if num % 4 == 0 :
    if num % 100 == 0 :
        if num % 400 == 0 :
            print("the year", num, "is a leap year")
        else :
            print("the year", num, "is not a leap year")
    else :
        print("the year", num, "is a leap year")
else :
    print("the year", num, "is not a leap year")