define tokens = 12, take = 0

gosub intro

do

   print "There are " \
   print tokens \
   print " tokens remaining."
   crlf
   print "How many would you like to take? " \

   input take

   if take > 3 or take < 1 then

      print "You must take between 1 to 3 tokens."

   endif

   if tokens - take < 0 then

      print "You cannot take that many."

   endif

   if take <= 3 and take >= 1 and tokens - take >= 0 then

      let tokens = tokens - take

      if tokens = 0 then

         bell
         print "Congratulations. You got the last token."
         pause
         end

      endif

      let take = 4 - take

      if tokens >= 15 then

         let take = 3

      endif

      if tokens <= 3 then

         let take = tokens

      endif

      print "I will take " \
      print take \
      print " of the tokens."

      let tokens = tokens - take

      if tokens = 0 then

         print "I got the last token. I win. Better luck next time."
         pause
         end

      endif

   endif

loop

sub intro

   cls
   print "NIM game"
   crlf
   print "Press any key to play..."
   cls

return