Bitwise XOR to find an odd number using C++

#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    // using XOR property: a ^ a = 0 and 0 ^ a = a
    int res = 0;
    for (int i = 0; i < n; i++) {
        res ^= a[i];
    }
    cout << res << '\n';
    return 0;
}