import java.util.Scanner

object Problem268 {
  def main(args: Array[String]) {
    val sc = new Scanner(System.in)
    val len = Array.fill(3)(sc.nextInt).sorted
    val roll = Array.fill(3)(sc.nextInt).sorted(Ordering[Int].reverse)

    // 最短の長さを一番多く巻く
    val roll1 = (len(0) + len(1)) * 2 * roll(0)
    val roll2 = (len(0) + len(2)) * 2 * roll(1)
    val roll3 = (len(1) + len(2)) * 2 * roll(2)
    val result = roll1 + roll2 + roll3

    println(result)
  }
}