# Write a function, which takes a non-negative integer (seconds)
# as input and returns the time in a human-readable format (HH:MM:SS)

# HH = hours, padded to 2 digits, range: 00 - 99
# MM = minutes, padded to 2 digits, range: 00 - 59
# SS = seconds, padded to 2 digits, range: 00 - 59
# The maximum time never exceeds 359999 (99:59:59)

def make_readable(seconds):
    pass
if __name__ == '__main__':
    assert make_readable(0) == "00:00:00"
    assert make_readable(5) == "00:00:05"
    assert make_readable(60) == "00:01:00"
    assert make_readable(86399) == "23:59:59"
    assert make_readable(359999) == "99:59:59"