class Yukicoder
  def initialize
    n = gets.chomp.to_i
    x = gets.chomp.split(' ').map(&:to_i).uniq.sort

    min_value = Float::INFINITY

    x.each_cons(2) do |a,b|
      min_value = [min_value, b-a].min
    end

    puts (min_value == Float::INFINITY)? 0 : min_value
  end
end

Yukicoder.new