#!/usr/bin/evn perl

use strict;
use warnings;

my $n = <>;
my $x = <>;
chomp $x;
my @array = split / /, $x;
@array = sort {$a <=> $b} @array;
my @after;
my $j = 0;
$after[0] = $array[0];
for(my $i = 1; $i < $n; $i++) {
	if($after[$j]  != $array[$i]) {
		$j++;
		$after[$j] = $array[$i];
	}
}

my $ans;
if($#after >= 1) {
	$ans = $after[1] - $after[0];
	for(my $i = 0; $i < $#after; $i++) {
		if($after[$i + 1] - $after[$i] < $ans) {
			$ans = $after[$i + 1] - $after[$i];
		}
	}
} else {
	$ans = 0;
}

print "$ans\n";

exit;