import calendar

print(calendar.calendar(2020))
print(calendar.month(2020,4))
print("the first week day: ",end="")
print(calendar.firstweekday())
print(calendar.monthlen(2020,5))
print(calendar.isleap(2020))
print(calendar.monthcalendar(2020,2))
print(calendar.leapdays(1999,2020))