The following text was written to the standard output stream when the ? program was executed from IntelliJ.
>>> display
2
4
6
8
10
12
14
16
18
20
22
>>> print first
2
>>> print last
22
>>> print 2
4
>>> print 8
16
>>> swap 4 16
>>> display
2
4
6
0
10
12
14
16
18
20
22
>>> swap 2 22
>>> display
2
0
6
0
10
12
14
16
18
20
22
>>> help
HELP - display a menu of commands
DISPLAY - display the list of numbers
PRINT - print a number (FIRST; LAST; nth)
SWAP - exchange two elements (nth;mth)
ADD - add a number to the list (FIRST;LAST
EXIT - terminate the execution of the program
>>> exit
Process finished with exit code 0