Complex Multiplication - KOTLIN

package com.company

import java.util.*

fun main() {
    val sc = Scanner(System.`in`)
    val n = sc.nextInt()
    val real = ArrayList<Long>()
    val imaginary = ArrayList<Long>()
    for (i in 0 until n) {
        val num = sc.nextLong()
        real.add(num)
    }
    for (i in 0 until n) {
        val num = sc.nextLong()
        imaginary.add(num)
    }
    val result = multiplyComplexNumbers(real, imaginary, n)
    println(result[0].toString() + " + (" + result[1] + ")i")
}

fun multiplyComplexNumbers(real: ArrayList<Long>, imaginary: ArrayList<Long>, n: Int): ArrayList<Long> {

    var result = ArrayList<Long>()
    result.add(1)
    result.add(0)
    for (i in 0 until n) {
        result = multiply(result[0], result[1], real[i], imaginary[i])
    }
    return result
}

fun multiply(a: Long, b: Long, x: Long, y: Long): ArrayList<Long> {
    // ax - by + i(bx + ay)
    val MOD: Long = 1000000007
    val result = ArrayList<Long>()
    result.add((a * x - b * y) % MOD)
    result.add((b * x + a * y) % MOD)
    return result
}