#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int main() {
    int n;
    cin >> n;
    int nums[n];
    for (int i = 0;i < n;i++) {
        cin >> nums[i];
    }
    sort(nums,nums + n);
    int pos = nums[n / 2],ans = 0;
    for (int i = 0;i < n;i++) {
        ans += abs(nums[i] - pos);
    }
    cout << ans << endl;
}