Mismatched Socks

#include <bits/stdc++.h>
using namespace std;

int n;
priority_queue<int> pq;

int main() {
  cin.tie(0)->sync_with_stdio(0);

  cin >> n;
  for (int i = 0, x; i < n; ++i) {
    cin >> x;
    pq.push(x);
  }

  int64_t ans = 0;

  while (pq.size() >= 2) {
    int most = pq.top(); pq.pop();
    int second_most = pq.top(); pq.pop();
    int max_pair = min(most, second_most);
    if (max_pair > 1) max_pair /= 2;          // adicionado
    most -= max_pair;
    second_most -= max_pair;
    ans += max_pair;
    if (most > 0) pq.push(most);
    if (second_most > 0) pq.push(second_most);
  }

  cout << ans << '\n';
}