def read_data():
    N = int(input())
    A = list(set(map(int, input().split())))
    return A

def solve(A):
    digits = len(bin(max(A))) - 2
    index = 1 << digits
    rank_upper_bound = min(digits, len(A))
    for rank in range(rank_upper_bound + 1):
        A.sort(reverse=True)
        Ar = A[rank]
        if Ar == 0:
            break
        while index and not Ar & index:
            index >>= 1
        for i in range(rank + 1, len(A)):
            if not A[i] & index:
                break
            A[i] ^= Ar
    return 1 << rank

N, A = read_data()
print(solve(A))