$ perl -Mstrict -we 'my @a = qw(a b c d);  my %h = map { $_++ } @a'
$ perl -Mstrict -we 'my @a = qw(a b c d e);my %h = map { $_++ } @a'
Odd number of elements in hash assignment at -e line 1.
$ 

##</code><code>##

s**lil*;  $*=join'',sort split q**;  s;.*;grr; &&s+(.(.)).+$2$1+; $; =
qq-$_-;s,.*,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$*,$/)