<s>[INST] import calendar
print(calendar.monthrange(2020, 1))   #output: (2, 31)
print(calendar.monthrange(2021, 1))   #output: (5, 31)

The monthrange() function prints two numbers. The first digit tells which day of the week the first day of the month falls on (where Monday is 0 and Sunday is 6), whereas the second digit shows the number of days in the month.

I'm trying to determine the leap years in a given range of years, and I'm having trouble understanding how this function can help me find the answer. The second value which is the number of the days in the month is always 31 on January. Can you explain how the monthrange function works and how to write a simple program that uses this function to find leap years in python?[/INST]