private fun List<Robot>.score(): Int {
        val quadrants = IntArray(4)
        val splitX = width / 2
        val splitY = height / 2

        mapNotNull { (p) ->
            when (p.x) {
                in 0 until splitX -> 0
                splitX -> null
                else -> 2
            }?.let { x ->
                when(p.y) {
                    in 0 until splitY -> 0
                    splitY -> null
                    else -> 1
                }?.let { y -> quadrants[x + y]++ }
            }
        }
        return quadrants.reduce(Int::times)
    }