player.onChat("3-9", function () {
    let height = 5;
    let length = 1;
    for (let i = 0; i < 4; i++) {
        for (let j = 0; j < height; j++) {
            agent.place(FORWARD);
            agent.move(UP, 1);
        }
        agent.move(DOWN, height);
        agent.move(RIGHT, length);
        height -= 1;
        length += 1;
    }
});