This free verse puzzle poem is also a working computer program which you can type into any version of the BASIC programming language.  The shareware programme Liberty Basic is recommended , as all you have to do is to paste the programme into the editor window.  You can also enjoy the poem just as it is, but when you get to the choice of doors, don't be tempted to take a peep at parts 2 and 3 until you have made your choice!

           
100 PRINT "You have followed an old map to Goblin"
110 PRINT "Mountain.  You find the place marked"
120 PRINT "TREASURE CAVE, and go in nervously."
130 PRINT
140 PRINT "The cave is dank and gloomy.  Your"
150 PRINT "footsteps make frightening echoes."
160 PRINT
170 PRINT "At the end of the cave are two doors:"
180 PRINT "a green one and a brown one -"
190 PRINT
200 PRINT "Which door will you choose?"
210 PRINT
220 PRINT "Type in GREEN or turn to PART 2"
230 PRINT "Type in BROWN or turn to PART 3"
240 PRINT
250 INPUT A$
260 IF A$ = "GREEN" THEN GOTO 300: REM GOBLIN
270 IF A$ = "BROWN" THEN GOTO 400: REM GOLD
280 GOTO 250
300 REM  PART 2
310 REM
320 PRINT "You have chosen the wrong door!"
330 PRINT "A huge goblin leaps out and gobbles"
340 PRINT "You up!"
350 END
400 REM  PART 3
410 REM
420 PRINT "You have chosen well!  Inside the"
430 PRINT "door is a huge chest crammed with"
440 PRINT "gleaming gold coins!"
999 END