class Bakery {
    private var flag:Array[Boolean]{self.rank==1};
    private var label:Array[Long]{self.rank==1};
    
    public def this(n:Int) {
	flag = new Array[Boolean](n,false);
	label = new Array[Long](n,0L);
    }

    private def nextLabel() {
	var max:Long = 0;
	for (var i:Int = 0; i < label.size; i++) {
	    if (label(i) > max) max = label(i);
	}
	return max+1;
    }

    private def someoneElseFirst(i:Int) {
	for (var k:Int = 0; k < label.size; k++) {
	    if (flag(k) && 
		((label(k) < label(i)) || ((label(k) == label(i)) && (k < i)))) 
		return true;
	}
	return false;
    }

    public def lock(i:Int) {
	// doorway section
	flag(i) = true;
	label(i) = nextLabel();
	
	// waiting section
	while (someoneElseFirst(i)) {}
    }
    
    public def unlock(i:Int) {
	flag(i) = false;
    }
}