#include <iostream>
#include <algorithm>
using namespace std;
const int N = 100010;
int n;
int q[N];
int main() {
    scanf("%d", &n);
    for (int i = 0; i < n; i ++ ) scanf("%d", &q[i]);
    sort(q, q + n);
    int res = 0;
    for (int i = 0; i < n; i ++ ) res += abs(q[i] - q[n / 2]);
    printf("%d\n", res);
    return 0;
}