## https://yukicoder.me/problems/no/2071

def shift(a):
    x = a % 2
    b = a >> 1
    b += x * 2 ** 15
    return b


def main():
    N = int(input())
    A = list(map(int, input().split()))
    if N >= 16:
        print(2 ** 16 - 1)
        return


    dp = {0}
    for a in A:
        new_dp = set()

        for _ in range(16):
            for x in dp:
                y = x | a
                new_dp.add(y)
            a = shift(a)
        dp = new_dp
    
    print(max(dp))









if __name__ == '__main__':
    main()