package main

import (
	"fmt"
	"math"
)

func main() {
	solve()
}

var B, N, ans int
var C [10]int

func solve() {
	fmt.Scan(&B, &N)
	for i := 0; i < N; i++ {
		fmt.Scan(&C[i])
	}
	ans = math.MaxInt64
	lo := 0
	hi := math.MaxInt64 / 30
	for hi-lo > 10 {
		loMid := (lo + lo + hi) / 3
		hiMid := (lo + hi + hi) / 3
		if calc(loMid) <= calc(hiMid) {
			hi = hiMid
		} else {
			lo = loMid
		}
	}
	for i := max(0, lo-100); i < lo+100; i++ {
		calc(i)
	}
	fmt.Println(ans)
}

func calc(a int) int {
	rest := B
	temp := 0
	for i := 0; i < N; i++ {
		temp += abs(a - C[i])
		rest += C[i] - a
	}
	if rest < 0 {
		return math.MaxInt64 / 3
	}
	ans = min(temp, ans)
	return temp
}

func abs(a int) int {
	if a < 0 {
		a *= -1
	}
	return a
}

func min(a, b int) int {
	if a > b {
		a = b
	}
	return a
}

func max(a, b int) int {
	if a < b {
		a = b
	}
	return a
}