#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>

//#include<bits/stdc++.h>


using namespace std;



int main() {


	int n;
	cin >> n;
	vector<long long int>p(n);
	for (int i = 0; i < n; i++)cin >> p[i];
	sort(p.begin(), p.end());

	long long int t;
	if (n%2)t = p[n / 2];
	else t = (p[n / 2] + p[n / 2 - 1]) / 2;
	long long int ans = 0;
	for (int i = 0; i < n; i++) {
		ans += abs(t - p[i]);
	}
	cout << ans << endl;

	return 0;




}