using System;

namespace ConsoleApp11
{
    class Program
    {
        static void Main(string[] args)
        {
            long min = 0;

            long N = long.Parse(Console.ReadLine());

            var input = Console.ReadLine().Split(' ');

            long[] X = new long[N];

            for(long i = 0; i < N; i++)
            {
                X[i] = long.Parse(input[i]);
            }

            for(long i = 0; i < N - i; i++)
            {
                for(long j = i + 1; j < N; j++)
                {
                    if(min == 0 && X[i] != X[j])
                    {
                        if(X[i] - X[j] > 0)
                        {
                            min = X[i] - X[j];
                        }
                        else if(X[j] - X[i] > 0)
                        {
                            min = X[j] - X[i];
                        }
                    }
                    else if(X[i] != X[j])
                    {
                        if(X[i] - X[j] > 0)
                        {
                            if(min > X[i] - X[j])
                            {
                                min = X[i] - X[j];
                            }
                        }
                        else if(X[j] - X[i] > 0)
                        {
                            if(min > X[j] - X[i])
                            {
                                min = X[j] - X[i];
                            }
                        }
                    }
                }
            }

            Console.WriteLine(min);
        }
    }
}