with Ada.Text_Io;
use Ada.Text_IO;

procedure partd is
   N:constant := 8;
   type Index is mod N;
   type Item_Array is array (Index) of character;
   
   protected type Buffering is
      entry Put(X: in character);
      entry Get(X: out character);
   
      private
      A:Item_Array;
      I,J : Index := 0;
      Count : Integer range 0..N := 0;
   end Buffering;

   protected body Buffering is
      entry Put(x: in character) when Count<N is
      begin
         A(I) := X;
         I := I+1;
         Count := Count+1;
      end Put;
      
      entry Get(X:out character) when Count>0 is
      begin
         x := A(J);
         J := J+1;
         Count := Count-1;
      end Get;
   end Buffering;
  
   My_Buffer : Buffering;
   x : character;

begin -- partd start

   My_Buffer.Put ('a');
   My_Buffer.Get (x);
   
put(x);
   
end partd;