Fletcher's checksum in Kotlin

gistfile1.kt

package com.drguildo.stdlib.algorithms

fun fletcher16(data: ByteArray): Int {
  var sum1 = 0
  var sum2 = 0

  for (d in data) {
    sum1 = (sum1 + d) % 255
    sum2 = (sum2 + sum1) % 255
  }

  return sum2.shl(8).or(sum1)
}

fun main(args: Array<String>) {
  var n = readLine()!!.toInt()

  for (i in 1..n)
    println(java.lang.String.format("%d %X", i, fletcher16(readLine()!!.toByteArray())))
}