using System;

namespace yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());
            string[] s = Console.ReadLine().Split(' ');
            int[] b = new int[a];
            int min = 0;
            int max=0;
            int ans = 0;
            
            for(int x = 0; x < a; x++)
            {
                b[x] = int.Parse(s[x]);
                if (b[x] == 0)
                {
                    continue;
                }
                for (int y = 1; y < a; y++)
                {
                    b[y] = int.Parse(s[y]);
                    if (b[x] > b[y])
                    {
                        max = b[x];
                        min = b[y];
                    }
                    else
                    {
                        max = b[y];
                        min = b[x];
                    }

                    if ( min != 0 && max != 0)
                    {
                        if (max == min)
                        {
                            if (ans==0||ans > min)
                                ans = min;
                        }
                        else
                        {
                            int c = max - min;
                            if (ans == 0)
                            {
                                ans = c;
                            }
                            if (ans > c)
                            {
                                ans = c;
                            }
                          
                        }
                    }

                }
               
            }
            Console.WriteLine(ans);
            
        }
    }
}