#!/usr/bin/perl

use strict;
use warnings;

my $n = <>;
my $str = <>;
chomp $str;
my @array = split / /, $str;
@array = sort {$a <=> $b} @array;

my $i = 1;
my $min;
my $flag = 0;
while($flag == 0) {
	$min = $array[$i] - $array[$i -1];
	$i++;
	if($min != 0) {
		$flag = 1;
		$i--;
	}
}

for(my $j = $i; $j < $n; $j++) {
	my $move = $array[$j] - $array[$j-1];
	if(($move != 0)and($move < $min)) {
		$min = $move;
	}
}

print "$min\n";

exit;