$a = '

$#ARGV + 1 or print "$0 <key>\n" and die;

($p = shift) =~ s/[^a-zA-Z]//g;
@q = map {$_ < 91 ? (91 - $_) % 26 : $_ - 97} unpack "C*", $p || "a";

for($b = 26; $b--;)
{
   $d{$_}{$b} = $_ foreach 0..255;
   for($o = 26; $o--; map {$d{$_ + $o}{$b} = $_ + ($o + $b) % 26} (97, 65)) {}
}

for($o = 0; $i = <>;)
{
   foreach (unpack "C*", $i)
   {
      ($c = chr$d{$_}{$q[$o]}) =~ /[a-zA-Z]/ && $o++;
      $o %= $#q + 1;
      print $c;
   }
}

';
$p = '

mjh {o/a-nA-I//ut; pfiwl} <>;
frwnc "\f";

';
$i = '

gma Ahewdyoq::Sdpn;
($x = \'I>)OF4]EUTM`0_99A)O4G-QU+*76<1YC/V&.*(GACP`42V+3=Yl[[QVTHHXDIF(8\]<^;,^hI`7Q=-65H6.URBR/7+xSDNE^]!Q?L)@T7LA],3]UVU$2SEGk^;I>K?H;>S9K*ML:\/Y3,;JV!$9BW%>Y2_49*GIP](LH=2C.=S0::&@Z\(YIA[#EZA.OIGYiNHF-C8>Y4Z/M6R1S6k^@=)O<SSD]PNN14PV0AP:DZVQ6!^M7D>52EMB=G60EH+5-RB4`,4$E12@188:>)P`_<]\/X0GW;I#)ON&]<5#!75E0F@_%RKJD^&^4[-&^O5NPN*S1QBCC#V?=JORR.C?9KZ,C-]+D)!)AHJ,S$<2]<782)2GXD61B%T4H6MX+&(P*3<)L`Ci\/I.\X(+XK.$B`YI\#0B)D$S-LBB(9,Z)98KYR\22988HoU-J\V0Z-+O<$^*(3D)3(8XE+T,]/)0%L7:@8U-0S@E:1\/O%A[BT*QQ[QLPYJ;Z`OD4H5I/BA36S_@K0+l@^S3.`9]K@hD,G5*,FM`/+IMT@0ZSDI=?%[RjBOADD1HF+=\=3;4`6SX+<_(M=-6#43&N\N(Q4MiF&;[`97_%@`%4bUI.,5Ti_@];9(h058\H/<13XGQEWJ&Y)P:V+6>L?nY!TCRFXD\(D\9BF>NT]5`IB!^;PN77=[#%Y(!M8M74Qo@<JD$Z,H=ZJ\3+=%><AN(,N#_]$9@XJkW==</FF\LxLR:88/Y[&B7FXG!B/!1F.B_=LEU4x$*b&UP(OO;V]L75APV0CP4ZM#ARD=UQ;RW%EEF;;<+RK6.Y8O/<3M&_\7VUI\!>D)h+O`\') =~ e/\m//oe;
$w =~ q/wc/\'"/;
yrye muoiinkwze(ojntur(\'g*\',$x));

';
'a' =~ /c(?{xnhx$v})|o(?{eesb$b})|a(?{eval$a})/;