import scala.math._
import scala.annotation._
import scala.collection._
import scala.collection.{mutable => mut}
import scala.util.control.Breaks.{breakable,break}

object Main {
  def main(args: Array[String]) {
    val sc = new java.util.Scanner(System.in)

    val k, a, b = sc.nextLong
    val l = k + 1

    val m =
      if (a + 2 >= b)
        l
      else {
        val l_ = l - a
        a + l_ / 2 * (b - a) + l % 2
      }
    println(m)
  }
}