def lpolacz (l1:Stream[Int], l2:Stream[Int]):Stream[Int]={
val h1#::t1=l1;
val h2#::t2=l2;
if(l1==Stream.empty){
l2
}else if (l2==Stream.empty) l1
else{
 h1#::h2#::lpolacz (t1,t2);
 }
 }
 val list1 = Stream.cons(1,Stream.cons(3,Stream.empty))
 val list2= Stream.cons(2,Stream.cons(4,Stream.empty))