N = int(input())
A = list(map(int, input().split()))
B = [0 for _ in range(100)]
for a in A:
    b = bin(a)[2:]
    b = b[::-1]
    for i in range(len(b)):
        if b[i]=="1":
            B[i]+=1
pos = B.index(0)
print(2**pos)