<?php
$bacon=array('a'=>'AAAAA', 'b'=>'AAAAB', 'c'=>'AAABA', 'd'=>'AAABB', 'e'=>'AABAA', 'f'=>'AABAB');
$word="the jOs to kIll fAr";

$word=str_replace(" ","",$word);
$word=preg_replace("![A-Z]!", "B", $word); 
$word=preg_replace("![a-z]!", "A", $word);
$word = preg_split("//u", $word, null, PREG_SPLIT_NO_EMPTY);
$word=array_chunk($word,5);
for($i=0; $i<count($word); $i++)  {
$letters.=implode($word[$i])." ";
}
$bacon1=array_flip($bacon);
$letters=str_replace($bacon,$bacon1,$letters);
$letters=str_replace(" ","",$letters);

echo $letters;