begin
 real
  a;
 begin
  real
   a;
  begin
   real
    a;
   begin
    real
     a;
    begin
     real
      a;
     begin
      real
       a;
      begin
       real
        a;
       begin
        real
         a;
        begin
         real
          a;
         begin
          real
           a;
          begin
           real
            a;
           begin
            real
             a;
            begin
             real
              a;
             begin
              real
               a;
              begin
               real
                a;

              end
             end
            end
           end
          end
         end
        end
       end
      end
     end
    end
   end
  end

 end

end