def METHOD_NAME(l: list):
    """ In-place sorting is fast, but we (may) need to purge rows that are broken.
        Purging broken rows is A) exceedingly uncommon, B) potentially VERY slow."""
    try:
        # first value should be a timestamp integer-like string, we get a ValueError if it isn't.
        l.sort(key=lambda x: int(x[0]))
    except ValueError:
        # get bad rows, pop them off, sort again
        bad_rows = []
        for i, row in enumerate(l, 0):  # enumerate in this context needs to start at 0
            try:
                int(row[0])
            except ValueError:
                bad_rows.append(i)
        for bad_row in reversed(bad_rows):
            l.pop(bad_row)  # SLOW.
        l.sort(key=lambda x: int(x[0]))