#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000
#define int long long 
int N;
int C[10];

int check(int a) {
	int sum = 0;
	rep(i, N) sum += abs(C[i] - a);
	return sum;
}


signed main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	int B;
	cin >> B >> N;
	if (N == 1) {
		cout << 0 << endl;
		return 0;
	}
	rep(i, N) cin >> C[i];
	int ok = 0, ng = 2000000000;
	rep(i, 100) {
		int mid = (ok + ng + 1) / 2;
		int left = check(ok);
		int right = check(ng);
		if (right > left) ng = mid;
		else ok = mid;
		//cout << ok << " " << ng << endl;
	}
	while (ok * N - check(0) > B) ok--;
	cout << check(ok) << endl;
	


    return 0;
}