#!/usr/bin/env perl

use strict;
use warnings;

my $n = <>;
my $k = <>;
my @array;
for(my $i = 0; $i < $n; $i++) {
	$array[$i] = <>;
}
@array = sort {$a <=> $b} @array;

my $ans = $array[$#array] - $array[0];
print "$ans\n";

exit;