#include <iostream>
#include <algorithm>
using namespace std;
const int N = 100100;
int a[N];
int n;
int main() {
scanf("%d", &n);
for (int i = 0; i < n; i ++) scanf("%d", &a[i]);
sort(a, a + n);
int res;
for (int i = 0; i < n; i ++) res += abs(a[i] - a[n / 2]);
printf("%d", res);
return 0;
}