class Calc0135
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @n = args.shift.first.to_i
    @xs = args.shift.map(&:to_i)
  end

  def run
    xs = @xs.uniq
    if xs.size == 1
      0
    else
      xs.sort.each_cons(2).map { |x1, x2| x2 - x1 }.min
    end
  end
end

puts Calc0135.new(STDIN.readlines).run if __FILE__ == $0