@a=A..Z;$c{$a[$_]}=$a[$_-13],$c{lc$a[$_]}=lc$a[$_-13]for 0..25;@p=split/!/,join("",<>),2;{">+"=>sub{print"Hello, world!"},"+["=>sub{$_=$p[1];s/./$c{$&}?$c{$&}:$&/eg;substr$_,28672,1,"";print},">>"=>sub{$_="18/b
18b/b
16/b3
16b/b
14/b b/
16b
12/4
12b/b
10/2b/
10b/b
9b2/
8b/b
6/b3
7/b
4/b2/
5/ 
3b b/
4b
/b3
b b
 b/";s/b/\\/g;s/\d+/$"x$&/eg;print}}->{substr$p[0],0,2}()