use POE;

POE::Session->create(
   inline_states => {
       trats_  => sub {$M=$_[HEAP]->{m}.$M},
       _start  => sub {
                   $_[HEAP]->{m} = $_;
                   $_[KERNEL]->yield(trats_);
               },
   }
) for split('',"\nrekcaH EOP rehtonA tsuJ");

POE::Kernel->run() and print $M;