#!/usr/bin/perl

use strict;
use warnings;

my $n = <>;
my $str = <>;
chomp $str; 
my @array = split / /, $str;

if($n < 1) {
	print "0\n";
	exit;
}

@array = reverse sort {$a <=> $b} @array;

my $ans = $array[0] - $array[1];

for(my $i = 0; $i < $n - 1; $i++) {
	if($array[$i] - $array[$i + 1] < $ans) {
		$ans = $array[$i] < $array[$i + 1];
	}
}

print "$ans\n";

exit;