import sys def main(): input = sys.stdin.read().split() N = int(input[0]) a_prime = list(map(int, input[1:N+1])) ans_prev = 0 A = [] for i in range(N): ai = a_prime[i] ^ ans_prev A.append(ai) max_len = min(60, i + 1) current_max = -1 for L in range(1, max_len + 1): start = i - L + 1 if start < 0: continue sub = A[start:i+1] m = L k = (m + 1) // 2 - 1 sub_sorted = sorted(sub) median = sub_sorted[k] if median > current_max: current_max = median ans_i = current_max ans_prev = ans_i print(ans_i) if __name__ == '__main__': main()