Calculator

import java.util.*
fun main(args: Array<String>) {
    val reader = Scanner(System.`in`)
    print("Zadaj prvé čslo: ")
        val first = reader.nextDouble()
    println("Zadaj druhé číslo:")
        var second = reader.nextDouble()
    println("Zadaj tretie číslo:")
        var third = reader.nextDouble()
    println("Zadaj štvrté číslo:")
        var fourth = reader.nextDouble()
    println("Zadaj piate číslo:")
        var fifth = reader.nextDouble()
    println("Zadaj šieste číslo:")
        var sixth = reader.nextDouble()
    println("Zadaj siedme číslo:")
        var seventh = reader.nextDouble()
    println("Zadaj ôsme číslo:")
        var eight = reader.nextDouble()
    println("Zadaj deviate číslo:")
        var ninth = reader.nextDouble()
        print("vyber si operáciu (+, -, *, /): ")
        val operator = reader.next()[0]
        val result: Double
        when (operator) {
            '+' -> result = first + second + third + fourth + fifth + sixth + seventh + eight + ninth
            '-' -> result = first - second - third - fourth - fifth - sixth - seventh - eight - ninth
            '*' -> result = first * second * third * fourth * fifth * sixth * seventh * eight * ninth
            '/' -> result = first / second / third / fourth / fifth / sixth / seventh / eight / ninth
            // operator doesn't match any case constant (+, -, *, /)
            else -> {
                System.out.printf("Error! operator is not correct")
                return
            }
        }
        System.out.printf("%.1f %c %.1f %c %.1f %c %.1f %c %.1f %c %.1f %c %.1f %c %.1f %c %.1f = %.1f", first, operator, second, operator, third, operator, fourth, operator, fifth, operator, sixth, operator, seventh, operator, eight, operator, ninth, result)
    }