#!perl -p0
$_=reverse,s!(\d)((\S.{46} )*\S|.{47}\S+.{47}|.{46}\S\S.{46}|.{45}\S{3}.{45})\K#|\S(\d).{45}( \S.{46})*\K#(?=\S)!7^$1^$4!se,s!(?<=(...)(.){46})#(?=(.))!$_="$2$1$3#";s/\b //g;$_.=$_^v7 x5;/1(\d)|(\d)6/?vec'x$5',$+,4:/35/?6:/45/||'#'!sgewhile/^
|#/
Note that non-ascii characters in the above source code will be escaped (such as \x9f).