#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
using namespace std;
const int N = 1e5 + 5;

int arr[N];

int main()
{
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) 
        scanf("%d", &arr[i]);
    sort(arr, arr+n);

    int warehouse = arr[n/2];
    int res = 0;
    for (int i = 0; i < n; ++i) 
        res += abs(warehouse - arr[i]);
    printf("%d", res);
    return 0;
}