<?php
$input = "++++++[>++++++++++++<-]>. >++++++++++[>++++++++++<-]>+. +++++++. . +++. >++++[>+++++++++++<-]>. <+++[>----<-]>. <<<<<+++[>+++++<-]>. >>. +++. . . >>+.";
$buff = array();
$output = '';
for($i = 0; $i < strlen($input); $i++){
  switch ($input[$i]){
  	case'+':++$buff[key($buff)];break;
  	case'-':--$buff[key($buff)];break;
  	case'>':
  	  if(! next($buff)){
  	    array_push($buff, 0);	
  	  }
  	  $buff[key($buff)] = current($buff);
  	break;
  	case'<':
  	  prev($buff);
  	  $buff[key($buff)] = current($buff);
  	break;
  	case'[':
  	  $k = 0;
  	  if($buff[key($buff)] == 0){
  	    while ($input[$i] != ']' OR $k > 0 ){
  	  	  if($input[++$i] == '[') ++$k;
  	  	  if($input[$i] == ']') --$k; 
  	    }
  	  }
  	break;
  	case']':
  	  $k = 0;
  	  if($buff[key($buff)] != 0){
  	  	while($input[$i] != '[' OR $k > 0){
  	  	  if($input[--$i] == ']') ++$k;
  	  	  if($input[$i] == '[') --$k;
  	  	}
  	  }
  	break;
  	case'.':
  	  $output .= chr($buff[key($buff)]);
  	break;
  	
  	default:break;
  }
}

echo $output;
?>