package main
import "fmt"

func main(){
  var(
    A int64
    B int64
    N int64
    M int64
  )
  fmt.Scan(&A,&B,&N,&M)
  if A>B{
    fmt.Println(B+(A-B)/(N+1))
  }else{
    fmt.Println(A+(B-A)/(M+1))
  }
}