$= = '_' eq '_';
$- = () = ('(', ')');
$* = $- * $- * $-;
$/ = $- + $*;
_: $" .= chr $/ + $* ** $-;
$/ = $/ >> $= || $* * $-;
$/ = $/ & ~$* / $- and goto _;
print $", "\n";