}
            house[nhouse].row = p[who].row;
            house[nhouse].col = p[who].col;
            nhouse += 1;
        }
        who = 1 - who; // santa; bot; santa; bot; ..., ..., ...
    }
    free(house);
    printf("Santa and santa bot delivered at least 1 present to %u houses.\n", nhouse);
}

void aoc201502(char *data, size_t len) {
    (void)len; // unused argument
    unsigned sqf = 0, f = 0;
    for (;;) {