import calendar


def next_leap_year(current_year: int) -> int:
    """ Prints out which year is the next leap year after current_year

    >>> next_leap_year(2019)
    2020
    >>> next_leap_year(2018)
    2020
    >>> next_leap_year(2020)
    2024
    """

    iter_year = current_year + 1
    while True:
        if calendar.isleap(iter_year):
            return iter_year