def time_to_mss(sectime):
    """
    Converts a number of seconds to m:ss format

    :param sectime: int, a number of seconds

    :return: str, sectime in m:ss
    """
    n_min = int(sectime / 60)
    n_sec = int(sectime % 60)
    if n_sec == 0:
        return '{0:d}:00'.format(n_min)
    elif n_sec < 10:
        return '{0:d}:0{1:d}'.format(n_min, n_sec)
    else:
        return '{0:d}:{1:d}'.format(n_min, n_sec)