b = gets.chomp.to_i
n = gets.chomp.to_i
c = []
n.times do
	c << gets.chomp.to_i
end
#p ave
min_step = Float::INFINITY
(0..b).each do |num|
	ave = (c.inject(:+) + num) / n
	step = 0
	(0...n).each do |i|
		step += (ave - c[i]).abs	
	end
	#p step
	min_step = [step, min_step].min
end
p min_step