import sys
n = int(input())
a = list(map(int, input().split()))
print(a)
max_xor_sum = 0
curr_xor = 0
for ci, ce in enumerate(a):
if ci == 0:
curr_xor = ce
else:
if curr_xor ^ ce > curr_xor + ce:
# print(ci)
curr_xor ^= ce
else:
max_xor_sum += curr_xor
# print(max_xor_sum)
curr_xor = ce
max_xor_sum += curr_xor
print(max_xor_sum)
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