it compiles but when i submit it says code is wrong - php

Question

Question: A string is said to be complete if it contains all the characters from a to z. Given a string, check if it complete or not.
Input
First line of the input contains the number of strings N. It is followed by N lines each contains a single string.
Output
For each test case print "YES" if the string is complete, else print "NO"
Constraints
1 <= N <= 10
The length of the string is at max 100 and the string contains only the characters a to z
YOU CAN CHECK HERE http://www.hackerearth.com/problem/algorithm/complete-string-4/
When i submit the PHP code , it shows the result is wrong
<?php
$allowedString = array('random','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z');
function execute($fileName = "3\nwyyga\nqwertyuioplkjhgfdsazxcvbnm\nejuxggfsts"){
global $allowedString;
//$handle = fopen($fileName, 'r');
$l=0;
$text = array();
$text = explode("\n", $fileName);
$z=0;
// print_r($text);
if ($text[0]>=1 && $text[0]<=10){
for($i=1;$i<=$text[0];$i++){
if(strlen($text[$i])>=26 && strlen($text[$i])<=100 ){
$count = 0;
for($z=1;$z<27;$z++){
$pos = strpos($text[$i], $allowedString[$z]);
if($pos === false){
continue;
}else{
$count++;
}
}
if($count == 26){
echo 'YES'."<br>";
}else{
echo 'NO'."<br>";
}
}else{
echo 'NO'."<br>";
}
}
}
}
execute();
?>

Answer 1

After a quick look at the page, it seems that the site is STDIO (Standard Input/Output) for input and output data rather than files. So, you shouldn't read/write data to a file.
Here is some code:
<?php
//This will input a file from Standard Input
$line = trim(fgets(STDIN));
//This will output the string to Standard Output
fwrite(STDOUT, $output);
?>