with Ada.Text_Io, Ada.Integer_Text_Io;
use Ada.Text_Io, Ada.Integer_Text_Io;

procedure Ex03b is
   N     : Natural;
   X     : Natural;
   Somme : Natural;
begin
   Get(N);
   
   --- Début algo ---
   Somme := 0;
   for I in 1..N loop
      Get(X);
      Somme := Somme + X * (N - I + 1);
   end loop;
   --- Fin   algo ---
   
   Put("La somme est : "); Put(Somme, 1);
end;