using System;
using System.Linq;

public class P0135 {
    public static void Main() {
        var n = int.Parse(Console.ReadLine().Trim());
        var x = Console.ReadLine().Trim().Split(' ').Select(int.Parse).ToList();
        x.Sort();
        var result = 1000001;
        for(int i=0; i<n-1; i++) {
            if(x[i] != x[i+1]) {
                result = Math.Min(Math.Abs(x[i] - x[i+1]), result);
            }
        }
        if(result == 1000001) {
            result = 0;
        }
        Console.WriteLine(result);
    }
}