The following text was written to the standard output stream when the ? program was executed from Netbeans.
/usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/java -javaagent:/opt/intellij-idea-community/lib/ >>>display blue green yellow pink red orange purple white brown black gray gold silver violet navyblue >>>print 1 blue >>>print 15 navyblue >>>swap 1 15 >>>display navyblue green yellow pink red orange purple white brown black gray gold silver violet blue >>>add first yellow >>>display yellow navyblue green yellow pink red orange purple white brown black gray gold silver violet blue >>>help HELP - display menu of commands DISPLAY - display the list of words PRINT - print a word (FIRST; LAST; nth) SWAP - exchange two elements (nth; mth) ADD - add a word to the list (FIRST; LAST) EXIT - terminate execution of the program >>>exit Process finished with exit code 0