#include <iostream>
#include <vector>
#include <deque>
 
using namespace std;
 
// Function to calculate MinMaxXoR
int calculateMinMaxXoR(const vector<int>& A, int N) {
    int MinMaxXoR = 0;
 
    for (int length = 2; length <= N; ++length) {
        deque<int> minDeque, maxDeque;
        for (int i = 0; i < N; ++i) {
            // Remove elements not in the current window
            if (!minDeque.empty() && minDeque.front() <= i - length) {
                minDeque.pop_front();
            }
            if (!maxDeque.empty() && maxDeque.front() <= i - length) {
                maxDeque.pop_front();
            }
 
            // Maintain deques in non-increasing order for min and max
            while (!minDeque.empty() && A[minDeque.back()] >= A[i]) {
                minDeque.pop_back();
            }
            while (!maxDeque.empty() && A[maxDeque.back()] <= A[i]) {
                maxDeque.pop_back();
            }
 
            minDeque.push_back(i);
            maxDeque.push_back(i);
 
            // Calculate XOR for the current window
            if (i >= length - 1) {
                int minVal = A[minDeque.front()];
                int maxVal = A[maxDeque.front()];
                MinMaxXoR ^= (minVal ^ maxVal);
            }
        }
    }
 
    return MinMaxXoR;
}
 
int main() {
    int N;
    cin >> N;
    vector<int> A(N);
    for (int i = 0; i < N; ++i) {
        cin >> A[i];
    }
 
    int result = calculateMinMaxXoR(A, N);
    cout << result << endl;
 
    return 0;
}