class program {

define half-turn() {
    turnleft();
    turnleft();
}

define test-for-two() {
    if (nextToABeeper) {
        pickbeeper();
        if (nextToABeeper) {
            turnoff();
        }
    }
}

define search-a-two() {
    test-for-two();
    iterate (4) {
        if (frontIsClear) {
            move();
            if (nextToABeeper) {
                search-a-two();
            }
            half-turn();
            move();
            half-turn();
        }
        turnleft();
    }
}

program() {
    search-a-two();
}

}