#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
 
#define MAX_N 500000
 
int A[MAX_N];
int minDeque[MAX_N];
int maxDeque[MAX_N];
 
int calculateMinMaxXoR(int N) {
    int MinMaxXoR = 0;
 
    for (int length = 2; length <= N; ++length) {
        int minFront = 0, minBack = 0;
        int maxFront = 0, maxBack = 0;
 
        for (int i = 0; i < N; ++i) {
            // Remove elements not in the current window
            if (minFront < minBack && minDeque[minFront] <= i - length) {
                ++minFront;
            }
            if (maxFront < maxBack && maxDeque[maxFront] <= i - length) {
                ++maxFront;
            }
 
            // Maintain deques in non-increasing order for min and max
            while (minFront < minBack && A[minDeque[minBack - 1]] >= A[i]) {
                --minBack;
            }
            while (maxFront < maxBack && A[maxDeque[maxBack - 1]] <= A[i]) {
                --maxBack;
            }
 
            minDeque[minBack++] = i;
            maxDeque[maxBack++] = i;
 
            // Calculate XOR for the current window
            if (i >= length - 1) {
                int minVal = A[minDeque[minFront]];
                int maxVal = A[maxDeque[maxFront]];
                MinMaxXoR ^= (minVal ^ maxVal);
            }
        }
    }
 
    return MinMaxXoR;
}
 
int main() {
    int N;
    scanf("%d", &N);
 
    for (int i = 0; i < N; ++i) {
        scanf("%d", &A[i]);
    }
 
    int result = calculateMinMaxXoR(N);
    printf("%d\n", result);
 
    return 0;
}