12441856.scala

object Solution {

    def main(args: Array[String]): Unit = {
    	val n = Console.in.readLine().toInt
    	val sl = (1 to n).map(i => (Console.in.readLine(),i))
    	//io.Source.stdin.getLines().take(1).map(_.toInt)
    	println(math.abs(sl.par.foldLeft(0){(l,e) =>
    		val i = e._2 - 1
    		val arr = e._1.split(" ")
    		l + arr(i).toInt - arr(n - i - 1).toInt
    	}))
    }
}