bool check(int x) {
    int num = 0;

    while (x != 0) {
        num += (x % 2);
        x /= 2;
    }

    if (num % 2 == 1) {
        return true;
    } else {
        return false;
    }
}

long thePerfectTeam(vector<int> employeeRating) {
    long res = 0;

    int n = (int) employeeRating.size();

    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            if (check(employeeRating[i] ^ employeeRating[j])) {
                res++;
            }
        }
    }

    return res;
}