{Винарский 16_19_л}
type
  list=^node;
  node=record
        elem: real;
        next: list;
       end;

function sum(var L: list): real;
var p: list; e1,e2: integer;
  begin
    if(L<>nil) then
      begin
        p:=L;
        while(p^.next^.next<>nil) do
          p:=p^.next;
        e1:=p^.elem;
        e2:=p^.next^.elem;
        sum:=e1+e2;
      end;
  end;