import scala.io._
object Main {
  def main(args: Array[String]) {
    val input = Source.fromInputStream(System.in)
    val lines = input.getLines.toSeq
         
    val A = lines.take(2).map(_.toInt)
    val B = lines.drop(2).map(_.toInt)
    var res = 0
         
    if(A(0) < A(1)) {res += A(0)}
    else {res += A(1)}
    if(B(0) < B(1)) {res += B(0)}
    else {res += B(1)}
         
    println(res)
  }
}