object Main extends App {
  val sc = new java.util.Scanner(System.in)
  val N, A, B = sc.nextLong()
  println(if ((B - A) % 2 == 0) {
    (B - A) / 2
  } else {
    (A - 1) min (N - B) + 1 + (B - A - 1) / 2
  })
}
