Covid Robot problem

CovidRobot.kt

interface Command {
    fun execute(robot: Robot)
}

class TurnLeft : Command {
    override fun execute(robot: Robot) {
        robot.rotateLeft()
    }
}

class TurnRight : Command {
    override fun execute(robot: Robot) {
        robot.rotateRight()
    }
}

class MoveForward : Command {
    override fun execute(robot: Robot) {
        robot.move()
    }
}

class Robot(
    private var x: Int,
    private var y: Int,
    private var direction: Char,
    private val maxX: Int,
    private val maxY: Int
) {
    private val directions = listOf('N', 'E', 'S', 'W')

    fun rotateLeft() {
        val currentIdx = directions.indexOf(direction)
        direction = directions[(currentIdx - 1 + directions.size) % directions.size]
    }

    fun rotateRight() {
        val currentIdx = directions.indexOf(direction)
        direction = directions[(currentIdx + 1) % directions.size]
    }

    fun move() {
        when (direction) {
            'N' -> if (y < maxY) y++
            'E' -> if (x < maxX) x++
            'S' -> if (y > 0) y--
            'W' -> if (x > 0) x--
        }
    }

    fun executeInstructions(commands: List<Command>) {
        for (command in commands) {
            command.execute(this)
        }
    }

    fun getPosition(): String {
        return "$x $y $direction"
    }
}

class CommandInterpreter {
    fun interpret(input: String): List<Command> {
        return input.map {
            when (it) {
                'L' -> TurnLeft()
                'R' -> TurnRight()
                'M' -> MoveForward()
                else -> throw InvalidCommandException("Invalid command: $it, only supported commands are \"L,R,M\"")
            }
        }
    }
}

class InvalidCommandException(message: String) : Exception(message)

fun main() {

    println("Please enter covid ward upper right coordinate separated by space : Example \"5 5\"")

    val gridSize: List<Int> = readLine()!!.split(" ").map { it.toInt() }
    val maxX = gridSize[0]
    val maxY = gridSize[1]

    println("Please enter robot's initial position: Example \"1 2 N\"")

    val initialPosition: List<String> = readLine()!!.split(" ")
    val x = initialPosition[0].toInt()
    val y = initialPosition[1].toInt()
    val direction = initialPosition[2].first()

    println("Please enter command: Example \"LMLMLMLMM\" ")

    val instructions: String = readLine()!!

    val robot = Robot(x, y, direction, maxX, maxY)
    val commandInterpreter = CommandInterpreter()

    val commands = commandInterpreter.interpret(instructions)
    robot.executeInstructions(commands)

    println("Here is the final position of the robot")
    println(robot.getPosition())
}