<?php
$_fp = fopen("php://stdin", "r");
fscanf($_fp,"%d %d",$n,$d);
$numbers = explode(" ",fgets($_fp));
$results = 0;
$inc = 0;
while($inc<$n){
    $j = $numbers[$n-$inc]; //einfach mal j rausgreifen
    $i = $j-$d; //wenn j-i = d dann i = j-d
    $k = $d+$j; // wenn k-j =d dann  k = d+j
    if(in_array($i,$numbers) && in_array($k,$numbers)){
        $results++;
    }
    $inc++;
}
echo $results;
?>