using System;
using System.Collections.Generic;
using System.Linq;

namespace Yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());

            List<int> ary = new List<int>();
            ary.AddRange(Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray());
            ary.Sort();

            int dif = 0;
            for (int i = 1; i < ary.Count; i++)
            {
                int tmp = ary[i] - ary[i - 1];

                if (tmp == 0)
                {
                    continue;
                }

                dif = dif == 0 ? tmp : dif > tmp ? tmp : dif;
            }
            Console.WriteLine(dif);
        }
    }
}