Links Creator PHP

<?php

  $ar = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20);
  $ar_key = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20);
  //URLs
  $wer=5;                 //How Many Parts?
  $count=count($ar);      //Count Values
  $prts=$count/$wer;      //How many values comes in every Part
  $i = 0; 
  $plus=$prts;
  $t_urls="";
  //Keywords
  $wer_key=5;                 //How Many Parts?
  $count_key=count($ar_key);      //Count Values
  $prts_key=$count_key/$wer_key;      //How many values comes in every Part
  $i_key = 0; 
  $plus_key=$prts_key;
  $t_keywords="";
  

for ($z = 0; $z < $wer; $z++) {
    $t_urls.="{";
    for ($i = $i; $i < $prts; $e=3) {
           $t_urls.= $ar[$i]."|";
           $i++;
    }   $t_urls.="}";
        
        $t_keywords.="{";
        for ($i_key = $i_key; $i_key < $prts_key; $e_key=3) {
           $t_keywords.= $ar_key[$i_key]."|";
           $i_key++;
    }$t_keywords.="}";
    
    $all="[".$t_urls." ".$t_keywords."]";
    $all=str_replace("|}","}",$all);
    echo $all;

    echo "\n";
// Plus minus things and empty the pockets
    $prts_key=$prts_key+$plus_key;
    $prts=$prts+$plus;
    $t_urls=""; //Empty total URLs pocket so it can contain new in next round
    $t_keywords=""; //Empty total keywords pocket so it can contain new in next round
}

?>