class Yukicoder
  def initialize
    remain = gets.to_i
    n = gets.to_i
    candy = []

    n.times do
      candy << gets.to_i
    end

    answer = 0

    if candy.size == 1
      puts "0"
      return
    end

    a = 0
    b = candy.max
    answer = candy.inject(:+)

    #0.upto(b) do |j|
    #  puts "num = #{candy.inject(0){|sum,i| sum += (j < i)? i-j : j-i}}"
    #end

    while a < b-2
      c = a + (b-a)/3
      d = [a + 2 * ((b-a)/3), b].min

      v1 = candy.inject(0){|sum,i| sum += (c < i)? i-c : c-i}
      v2 = candy.inject(0){|sum,i| sum += (d < i)? i-d : d-i}

      if v1 < v2
        b = d
      else
        a = c+1
      end
    end

    min_val = Float::INFINITY

    a.upto(b) do |j|
      min_val = [min_val, candy.inject(0){|sum,i| sum += (j < i)? i-j : j-i}].min
    end
    puts min_val
  end
end

Yukicoder.new