text
next(text s)
{
    integer c, e, l;
    index v;
    data d;

    l = ~s;
    while (l) {
        v[-s[l -= 1]] += 1;
    }

    for (c, e in v) {
        b_form(d, "%d%c", e, -c);
    }

    return d;
}

integer
depth(text s, integer i, record r)
{
    integer d;

    d = 0;
    r_j_integer(d, r, s);
    if (d <= 0) {
        i += 1;
        d += d ? i : -i;
        r[s] = d;
        i = depth(next(s), i, r);
        d = r[s];
        if (d <= 0) {
            r[s] = d = i + 1;
        }
    }

    return d;
}

integer
main(void)
{
    integer d, e, i;
    record r;
    list l;

    d = 0;
    i = 1000000;
    while (i) {
        i -= 1;
        e = depth(itoa(i), 0, r);
        if (e == d) {
            lb_p_integer(l, i);
        } elif (d < e) {
            d = e;
            l_clear(l);
            lb_p_integer(l, i);
        }
    }

    o_("longest length is ", d, "\n");
    while (l_o_integer(i, l, 0)) {
        text s;

        o_("\n", i, "\n");
        e = d - 1;
        s = itoa(i);
        while (e) {
            o_(s = next(s), "\n");
            e -= 1;
        }
    }

    return 0;
}