import java.util.Scanner

object Main extends App {
  val sc = new Scanner(System.in)
  val a, b, n, m = sc.nextLong
  val set1 = Seq(a, b).min
  val a1 = a - set1
  val b1 = b - set1
  val ans = set1 + Seq(a1 / n, b1 / m).max
  println(ans)
}