import scala.io.StdIn

object Main {

  def main(args: Array[String]): Unit = {
    val n = StdIn.readLine().toInt
    val h = StdIn.readLine().toInt
    val w = StdIn.readLine().toInt
    val ans = (n - h + 1) * (n - w + 1)
    println(ans)
  }

}
