using System.Linq;
using System.Collections.Generic;
using System;

public class Hello
{
    public static void Main()
    {
        var b = int.Parse(Console.ReadLine().Trim());
        var n = int.Parse(Console.ReadLine().Trim());
        var a = new int[n];
        var amax = 0; var amin = int.MaxValue; var asum = 0;
        for (int i = 0; i < n; i++)
        {
            a[i] = int.Parse(Console.ReadLine().Trim());
            amax = Math.Max(amax, a[i]);
            amin = Math.Min(amin, a[i]);
            asum += a[i];
        }
        var ans = new List<int>();
        for (int i = amin; i <= amax; i++)
        {
            var w = getAns(a, b, asum, n, i);
            if (w != -1) ans.Add(w);
        }
        Console.WriteLine(ans.Min());
    }
    public static int getAns(int[] a, int b, int asum, int n, int t)
    {
        if (asum + b < t * n) return -1;
        if (asum + b == t * n)
        {
            var c = a.Where(x => x - t > 0).Select(x => x - t).Sum();
            return b + c * 2;
        }
        var cm = a.Where(x => x - t < 0).Select(x => x - t).Sum();
        var cp = a.Where(x => x - t > 0).Select(x => x - t).Sum();
        return cp - cm;
    }
}