#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    
    int N;
    cin >> N;
    vector<long long> V(N);
    for ( int i = 0; i < N; i++ ) {
        cin >> V[i];
    }
    sort( V.begin(), V.end() );
    
    long long mid = V[N/2];
    
    // cout << mid << endl;
    
    long long ans = 0;
    for ( int i = 0; i < N; i++ ) {
        ans += abs( mid - V[i] );
    }
    
    cout << ans << endl;
    
    return 0;
}