Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McNugget number is
the total number of McDonald's Chicken McNuggets in any number of boxes.
In the United Kingdom, the original boxes (prior to the introduction of
the Happy Meal-sized nugget boxes) were of 6, 9, and 20 nuggets.

Task

Calculate (from 0 up to a limit of 100) the largest non-McNuggets
number (a number n which cannot be expressed with 6x + 9y + 20z = n
where x, y and z are natural numbers).




with Ada.Text_IO; use Ada.Text_IO;
 
procedure McNugget is
   Limit : constant                      := 100;
   List  : array (0 .. Limit) of Boolean := (others => False);
   N     : Integer;
begin
   for A in 0 .. Limit / 6 loop
      for B in 0 .. Limit / 9 loop
         for C in 0 .. Limit / 20 loop
            N := A * 6 + B * 9 + C * 20;
            if N <= 100 then
               List (N) := True;
            end if;
         end loop;
      end loop;
   end loop;
   for N in reverse 1 .. Limit loop
      if not List (N) then
         Put_Line ("The largest non McNugget number is:" & Integer'Image (N));
         exit;
      end if;
   end loop;
end McNugget;