class program {
	void east(){
		while (notFacingEast)
			turnleft();
	}

	void west(){
		while (notFacingWest)
			turnleft();
	}

	void north(){
		while (notFacingNorth)
			turnleft();
	}

	void south(){
		while (notFacingSouth)
			turnleft();
	}
	
	void turnright(){
		iterate (3)
			turnleft();
	}

	void pickAll(){
		while (nextToABeeper)
			pickbeeper();
	}

	void putAll(){
		while (anyBeepersInBeeperBag)
			putbeeper();
	}

	void pickN(n){
		iterate(n) pickbeeper();
	}

	void swapBeeperBag(){
		if (anyBeepersInBeeperBag){
			putbeeper();
			swapBeeperBag();
			putbeeper();
		} else pickAll();
	}

	void compare(n){
		if (anyBeepersInBeeperBag){
			putbeeper();
			compare(succ(n));
		} else {
			pickN(n);

			iterate (n){
				if (nextToABeeper)
					pickbeeper();
				else
					south();
			}

			if (nextToABeeper || facingSouth)
				south();
			else
				north();

			putAll();
			pickN(n);
		}
	}

	void continueCandidate(){
		while (frontIsClear){
			move();

			compare(0);

			if (facingNorth){
				east();
				continueCandidate();
			} else {
				east();
				return();
			}
		}
	}

	void findCandidate(){
		while (iszero(0)){
			compare(0);

			if (facingSouth)
				swapBeeperBag();
			east();

			continueCandidate();

			if (frontIsClear)
				move();
			else return();
		}
	}

	void checkCandidatePositive(d){
		west();
		if (frontIsBlocked){
			if (iszero(d)){
				putAll();
				turnoff();
			} else {
				turnoff();
			}
		}
		move();

		compare(0);

		if (notNextToABeeper)
			north();

		if (facingNorth) {
			checkCandidatePositive(succ(d));
		} else {
			if (iszero(d)){
				checkCandidateNegative(1);
			} else {
				checkCandidatePositive(pred(d));
			}
		}
	}

	void checkCandidateNegative(d){
		west();
		if (frontIsBlocked){
			putAll();
			turnoff();
		}
		move();

		compare(0);

		if (notNextToABeeper)
			north();

		if (facingNorth){
			if (iszero(d)){
				checkCandidatePositive(1);
			} else {
				checkCandidateNegative(pred(d));
			}
		} else {
			checkCandidateNegative(succ(d));
		}
	}

	program(){
		east();
		findCandidate();

		compare(0);

		if (notNextToABeeper)
			north();

		if (facingNorth){
			checkCandidatePositive(1);
		} else {
			checkCandidateNegative(1);
		}
	}
}