use v5.16.3;

my $N = <>;
my $K = <>;
my @a = <>;

chomp ($N,$K);


my $max = 1;
my $min = 1000;

for my $n (@a) {
    chomp $n;
    $min = $n if $n <= $min;
    $max = $n if $n >= $max;
}
# say $min;
# say $max;
say int( ( $max - $min ) );