int lao(void) {
    int stats[9*3 + 1] = {0};
    stats[0] = 1;
    int lucky;
    int i, j, k;
    for (i = 0; i < 3; ++i) {
        for (j = 9 * i; j >= 0; --j) {
            for (k = 9; k > 0; --k) {
                stats[j + k] += stats[j];
            }
        }
    }

    lucky = 0;
    for (i = 0; i < 9*3+1; ++i) {
        int count = stats[i];
        lucky += count*count;
    }
    return lucky;
}