val llist=
{
    def zmien(s1:Stream[Int],s2:Stream[Int],mark:String):Stream[Int]=
    {
       val p1#::xs1 =s1
       val p2#::xs2=s2
       mark match {
         case "+" => (p1+p2)#::zmien(xs1,xs2,"+")
         case "-" => (p1-p2)#::zmien(xs1,xs2,"-")
         case "*" => (p1*p2)#::zmien(xs1,xs2,"*")
         case "/" => (p1/p2)#::zmien(xs1,xs2,"/")
       }

      }
    val l1 = Stream.cons(5,Stream.cons(7,Stream.cons(4,Stream.cons(10,Stream.empty))))
    val l2 = Stream.cons(1,Stream.cons(2,Stream.cons(3,Stream.empty)))

    zmien(l1,l2,"+")
  //  println( (zmien(l1,l2,"+")).toList )
}