HW2
Chrome devtools (this solution rely on the Chrome Devtools. It cannot run as a normal JavaScript file.)
// Note: $ + '' equals to "'function $(selector, [startNode]) { [Command Line API] }'" in Chrome Devtools.
_ = $ + ''
$1 = 2 / 2
$3 = 2 + $1
$4 = 2 + 2
$6 = 2 * $3
$12 = $3 * $4
$18 = $12 + $6
$13 = $3 * $4 + $1
$29 = $13 * 2 + $3
'H' + _[$12] + _[$13] + _[$13] + _[$6] + ', W' + _[$6] + _[$18] + _[$13] + _[$29] + '!'