Nested If Statements Problem

# As you surely know, due to some astronomical reasons, years may be leap or common. The former are 366 days long, while the latter are 365 days long.

# Since the introduction of the Gregorian calendar (in 1582), the following rule is used to determine the kind of year:

# if the year number isn't divisible by four, it's a common year;
# otherwise, if the year number isn't divisible by 100, it's a leap year;
# otherwise, if the year number isn't divisible by 400, it's a common year;
# otherwise, it's a leap year.


year = int(input("Enter a year: "))

if year < 1582:
    print("Not within Gregorian Calendar Period")
    
else :
    if year%4 != 0:
        year = "common year"
    elif year%100 != 0 :
        year = "leap year"
    elif year%400 != 0 :
        year = "common year"
    else:
        year = "leap year"
    print ("The entered year is a "+ year+"!")