#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<30;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int b, n;
int c[10];

int main() {
	cin >> b >> n;
	REP(i, n) scanf("%d", c + i);
	
	int mi = INF;
	REP(i, n) chmin(mi, c[i]);
	REP(i, n) c[i] -= mi;
	
	int ans = INF;
	int l = -1, r = INF;
	
	while (r - l > 1) {
		int m = (r + l) / 2;
		
		ll cnt = b;
		REP(i, n) cnt += c[i] - m;
		
		int up = 0, down = 0;
		REP(i, n) {
			if (c[i] > m) up++;
			if (c[i] < m) down++;
		}
		
		if (cnt >= 0) {
			ll now = 0;
			REP(i, n) now += abs(c[i] - m);
			chmin(ans, now);
		}
		
		if (cnt < 0) r = m;
		else if (down >= up) r = m;
		else l = m;
	}
	
	cout << ans << endl;
	
	return 0;
}