#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  long long int arr[n], sum = 0;
  for (int i = 0; i < n; i++) cin >> arr[n];
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      sum += arr[i] ^ arr[j];
    }
  }
  cout << (sum * 2) << endl;
}
