The following text was written to the standard output stream when the ? program was executed from IntelliJ.
>>> help HELP - display a menu of commands DISPLAY - display the list of numbers PRINT - print a String (FIRST;LAST;nth) SWAP - exchange two elements (nth;mth) ADD - add a String to the list (FIRST;LAST) EXIT - terminate execution of the program >>> display dog boat computer screen wire cart board water boil float high sit >>> print first dog >>> print last sit >>> print 3 computer >>> print 18 null >>> swap 1 2 >>> display boat dog computer screen wire cart board water boil float high sit >>> swap 1 18 >>> display null dog computer screen wire cart board water boil float high sit >>> help HELP - display a menu of commands DISPLAY - display the list of numbers PRINT - print a String (FIRST;LAST;nth) SWAP - exchange two elements (nth;mth) ADD - add a String to the list (FIRST;LAST) EXIT - terminate execution of the program >>> add first two >>> add last three >>> showwords ### Unrecognizable command: showwords >>> display two null dog computer screen wire cart board water boil float high sit three >>> exit