BEGIN{$SIG{__WARN__}=sub{$_=pop;y-_- -;print/".*(.)"/;
truncate$0,-1+-s$0;exec$0;}}//rekcaH_lreP_rehtona_tsuJ

##</code><code>##

BEGIN{$|=$SIG{__WARN__}=sub{$_=$_[0];y-_- -;print/(.)"$/;seek _,-open(_
,"+<$0"),2;truncate _,tell _;close _;exec$0}}//rekcaH_lreP_rehtona_tsuJ