def get_missing_interval(all_intervals, i_min=0, i_max=32):
    """Return a list of missing interval in all_interval
    @all_interval: list of (int, int)
    @i_min: int, minimal missing interval bound
    @i_max: int, maximal missing interval bound"""
    my_intervals = all_intervals[:]
    my_intervals.sort()
    my_intervals.append((i_max, i_max))
    missing_i = []
    last_pos = i_min
    for start, stop in my_intervals:
        if last_pos != start:
            missing_i.append((last_pos, start))
        last_pos = stop
    return missing_i
