def add_leading_gaps(t_aligned, s_aligned, i, j):
    """Add the leading gaps to alignments."""
    for _ in range(i):
        t_aligned = t_aligned[:0] + '-' + t_aligned[0:]
    for _ in range(j):
        s_aligned = s_aligned[:0] + '-' + s_aligned[0:]  # pragma: no cover
    return s_aligned, t_aligned