n = int(input())
a = list(map(int, input().split()))

res = sum(a)

for x in a:
    res |= x

cnt = 0
rem = res
bits = []
while rem != 0:
    if rem % 2 == 0:
        bits.append(cnt)
    rem //= 2
    cnt += 1

for bit in bits:
    flag = 2 ** bit
    sub = reversed(sorted(x%flag for x in a))
    s = 0
    for x in sub:
        s += x
        if s & flag:
            res |= flag
            break

print(res)