public static int sansaXor(List<Integer> arr) {
        int n = arr.size();
        if (n % 2 == 0) {
            return 0; 
        } else {
            int result = 0;
            for (int i = 0; i < n; i += 2) {
                result ^= arr.get(i); 
            }
            return result;
        }
    }