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

class Magatro
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        bool[] point = new bool[1000001];
        string[] s = Console.ReadLine().Split(' ');
        for(int i = 0; i < N; i++)
        {
            point[int.Parse(s[i])] = true;
        }
        int min = int.MaxValue;
        bool a=false;
        int sta = 0;
        bool k = false;
        for(int i = 0; i <= 1000000; i++)
        {
            if (!k)
            {
                if (point[i])
                {
                    sta = i;
                    k = true;
                }
            }
            else
            {
                if (point[i])
                {
                    min = Math.Min(min, i - sta);
                    a = true;
                    sta = i;
                }
            }
        }
        if (a)
        {
            Console.WriteLine(min);
        }
        else
        {
            Console.WriteLine(0);
        }
    }
}