Backpacking

input/Backpacking.scala:5: error: expected start of definition
def main(): Unit = {
^
one error found

import scala.io.StdIn.readLine

//TIP To <b>Run</b> code, press <shortcut actionId="Run"/> or click the <icon src="AllIcons.Actions.Execute"/> icon in the gutter.
@main
def main(): Unit = {
  val input = readLine()
  val A = input.charAt(0).toString.toInt
  val B = input.charAt(2).toString.toInt

  val O: Int = A + B

  println(O)
}