using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yukicoderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string N = Console.ReadLine();
            string X = Console.ReadLine();
            string[] kyoristr = X.Split(' ');
            int num = int.Parse(N);
            int[] kyori = new int[num];
            int ans = 0;
            bool flg = false;
            for(int i=0;i<kyori.Length;i++)
            {
                kyori[i] = int.Parse(kyoristr[i]);
            }
            for(int i=0;i<kyori.Length-1;i++)
            {
                int max = 0;
                int min = 0;
                if (kyori[i] == kyori[i + 1])
                {
                    ans = kyori[i];
                    flg = true;
                    continue;
                }
                for (int j=i+1;j<kyori.Length;j++)
                {
                    if (kyori[i] < kyori[j])
                    {
                        max = kyori[j];
                        min = kyori[i];
                    }
                    else
                    {
                        min = kyori[j];
                        max = kyori[i];
                    }
                    ans = max - min;
                }
            }
            if(flg==false)
            {
                Console.WriteLine(ans);
            }
            else
            {
                Console.WriteLine(ans);
            }
        }
        
    }
}