OP can probably extrapolate, and maybe that's why the parent stops just short of actually answering the original question: how to remove spaces, but only in the location field -- or learn from some other replies.
But just in case the assumption above is wrong, assign $2 to a named var ($second maybe) and remove spaces:
$second =~ s/\s*//g;
say "C/D/E/F - $second";
BUT that's not really the point of this post; rather (perhaps because /me is suffering brain-freeze, why the heck is the second capture ((.*\S)) a-greedy-anything followed by anything-not-whitespace working?
Y::R::E isn't helping this morning; neither is a recheck of (some obvious parts of) Mastering Regular Expressions
And in case my brain-freeze isn't clear, that chill is telling me that s+(.*\S)\s+(\S+) should capture the location-field and everything else up to the last space, before "HA". That's obviously wrong, but why?
Can someone, please, provide a the meat for a slap my forehead, grunt "Duh!" moment?