if a in [1..4] then write('few');
   if a in [5..9] then write('several');
   if a in [10..19] then write('pack');
   if a in [20..49] then write('lots');
   if a in [50..99] then write('horde');
   if a in [100..249] then write('throng');
   if a in [250..499] then write('swarm');
   if a in [500..999] then write('zounds');
   if a > 999 then write('legion');

Got same problem and my program is identical, have you found what the issue is ?

new line

Try through a "case"

case of a
1..4:write('few');
5..9:write('several');
...
1000 2000..:write('legion');
end;
end.