    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)
}
}