Hackertank beginner challenge: https://www.hackerrank.com/contests/noob/challenges/hackertank/problem

hackertank.php

<?php
$_fp = fopen("php://stdin", "r");
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
while($f = fgets($_fp)){
   $lines[] = $f;
}
$bugNum = intval($lines[0]);
$bugs = array_merge(explode(' ',$lines[1]));
 // print_r($bugs);                   
$mylvl = 1;
$myHealth = 10;
$kills = 0;
$allkills = 0; 
for($i = 0; $i<=$bugNum-1;$i++){
    $buglvl = $bugs[$i];
  
    
 // print $buglvl;
   
    
    if($buglvl == $mylvl){
        
       $myHealth = $myHealth - $buglvl;
       
       if($myHealth<0){
            echo "You have died. Reached level $mylvl and killed $allkills bugs";
            break;
        }
        $allkills +=1; 
        $kills +=1;
    }
    
    elseif($buglvl < $mylvl){
       $myHealth = $myHealth - 1;
       if($myHealth<0){
                  echo "You have died. Reached level $mylvl and killed $allkills bugs";    
            break;
        }
          $allkills +=1; 
         $kills +=1;
    }
    elseif($buglvl > $mylvl){
       $myHealth = $myHealth - ($buglvl*2);
        
       if($myHealth<0){
                 echo "You have died. Reached level $mylvl and killed $allkills bugs";
            break;
        }
          $allkills +=1; 
        $kills +=1;
    }
    
     if($kills == 3){
        $mylvl +=1;
        $myHealth =15;
        $kills = 0;
    }
   
}
    if($myHealth>0){
         echo "You have won! Reached level $mylvl and killed $allkills bugs";
    }
?>