<?php
    $n = trim(fgets(STDIN));
    $k = trim(fgets(STDIN));

    $max = trim(fgets(STDIN));
    $min = $max;

    for ($i = 1; $i < $n; $i++) {
        $num = trim(fgets(STDIN));
        if ($num > $max) {
            $max = $num;
        } elseif ($num < $min) {
            $min = $num;
        }
    }
    
    echo ($max - $min) . "\n";