using System.Collections.Generic;
using System;
using System.Drawing;
namespace yukicoder
{
    class Program
    {

        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            var str = Console.ReadLine().Split(" ");
            int n = 0, ans = 0 , temp = 0;
            
            List<int> list = new List<int>(N);
            
            for(int i = 0; i < N; i++)
            {
                list.Add(int.Parse(str[i]));
                
                if (list[n] == 0)
                {
                    list.RemoveAt(n);
                    n--;
                }
                n++;
            }

            list.Sort();

            

            if (list.Count < 2) //配列が1以下
            {
                Console.WriteLine("0");
            }
            else if (!(list.Count < 2))
            {
                temp = list[list.Count - 1];
            }


            for (int j = 0; j < list.Count  ; j++)
            {
                
                ans = list[j + 1] - list[j];
                if(ans < temp && !(list.Count <= 2)  || j == list.Count - 2 && !(list.Count <= 2))
                {
                    if(j == list.Count - 2)
                    {
                        Console.WriteLine(temp);
                        break;
                    }
                    else if (list[0] == list[list.Count - 1])
                    {
                        Console.WriteLine(list[0]);
                        break;
                    }
                    
                    else if (list[j + 1] == list[j])
                    {
                        temp = list[j + 1] / list[j];
                    }
                    else
                    {
                        temp = ans;
                    }
                }
                else if (list.Count <= 2 && !(list[0] == list[1]))
                {
                    Console.WriteLine(list[j + 1] - list[j]);
                    break;
                }
                else if(list[0] == list[1])
                {
                    Console.WriteLine(temp);
                    break;
                }
            }
        }
    }
}