#include <algorithm>
#include <vector>
#include <cfloat>
#include <string>
#include <cmath>
#include <set>
#include <cstdlib>
#include <map>
#include <ctime>
#include <iomanip>
#include <functional>
#include <deque>
#include <iostream>
#include <cstring>
#include <queue>
#include <cstdio>
#include <stack>
#include <climits>
#include <cctype>

using namespace std;

typedef long long ll;

int main() {
	int b;
	cin >> b;
	int n;
	cin >> n;
	ll sum = 0;
	int c[10];
	for (int i = 0; i < n; i++) {
		cin >> c[i];
		sum += c[i];
	}
	int ans = 1000000000;
	ll l = 0, r = sum + b;
	for (int i = 0; i < 100; i++) {
		ll p = (l + r) / 2;
		ll t = 0;
		for (int i = 0; i < n; i++) {
			t += abs(c[i] - p);
		}
		if (t < ans) {
			r = p;
			ans = t;
		}else {
			l = p;
		}
	}
	cout << ans << endl;
}