<?php

$input_lines = trim(fgets(STDIN));
$input_lines = str_replace(array("\r\n","\r","\n"), "", $input_lines);

foreach(str_split($input_lines) as $key => $value){
	print(decryptPos($value,$key+1));
}

function decryptPos($i_str,$i_count){
	$defStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	$tmpPos = strpos($defStr, $i_str);
	$tmpPos =  ($tmpPos - $i_count) % strlen($defStr);
	return substr($defStr,$tmpPos,1);
}
function encryptPos($i_str,$i_count){
	$defStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	$tmpPos = strpos($defStr, $i_str);
	$tmpPos =  ($tmpPos + $i_count) % strlen($defStr);
	return substr($defStr,$tmpPos,1);
}