[백준] 3046번 : R2 - Kotlin(코틀린)

https://www.acmicpc.net/problem/3046

import java.util.*;
fun main(args: Array<String>) {
    val sc=Scanner(System.`in`)
    var r=sc.nextInt()
    var s=sc.nextInt()
    print(2*s-r)
}