import sys

sys.setrecursionlimit(10**9)

N = int(input())
A = list(map(int, input().split()))
ans = 0


def shift(x):
    return x // 2 + 2**15 * (x % 2)


def dfs(v, i):
    global ans
    if i == N:
        # if ans < v:
        # print(bin(v))
        ans = max(v, ans)
        return
    # p = 0
    # while 2**p < A[i]:
    # p += 1
    dfs(v | A[i], i + 1)
    x = A[i]
    # print(p)
    for j in range(15):
        x = shift(x)
        # print(f"x = {x}, v={v}")
        dfs(v | x, i + 1)


dfs(0, 0)
print(ans)