#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <fstream>
#include <set>
#include <utility>
#include <algorithm>
#include <queue>
#include <stack>
#include <deque>
#include <numeric>
#include <sstream>
#include <list>
#include <map>
#include <functional>
#include <iterator>

#define rep(i,p,n) for(int i=(int)p;i<(int)n;i++)
#define repp(i,p,n) for(int i=(int)p;i>=(int)n;i--)
#define Sort(x) sort(x.begin(),x.end())
#define PSort(x) sort(begin(x), end(x), pairCompare)
#define ll long long
#define INF 2000000000
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define PI 3.14159265358979
int dx[4] = { -1,0,1,0 }, dy[4] = { 0,1,0,-1 };
using namespace std;

int main(){	
	int n;
	cin >> n;
	vector<ll> v(n);
	rep(i, 0, n)cin >> v[i];
	Sort(v);
	ll middle;
	middle = v[v.size() / 2];

	ll ans = 0;
	rep(i, 0, n) {
		ans += abs(v[i] - middle);
	}
	cout << (long long int)ans << endl;
	
	return 0;
}