#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
const int N = 1000010;
int a[N];
int n;
int main() {
cin >> n;
for (int i = 0; i < n; i++) cin >> a[i];
sort(a, a + n);
int x = a[n / 2];
int sum = 0;
for (int i = 0; i < n; i++) {
sum += abs(x - a[i]);
}
cout << sum << endl;
return 0;
}