#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;
  vector<int> v(n);

  REP (i, n) cin >> v[i];
  sort(v.begin(), v.end());

  long long sum = 0;
  REP (i, n) sum += abs(v[i] - v[n/2]);

  cout << sum << endl;
  
  return 0;
}