Hacker Rank Warmup - Very Big Sum

VeryBigSum.scala

//
// Code for: https://www.hackerrank.com/challenges/a-very-big-sum
//

object Solution {

    def main(args: Array[String]) {
        val num = readInt()
            
        // See if number is positive or negative
        def pos(s:String):Long = if(s.head == '1') s.toLong else ((s.toLong) * -1)
        
        // Read numbers, map to positive or negative Longs, then sum
        val output = readLine().split(' ').toList.map(x => pos(x)).sum
        println(output)
    }
}