import sys
readline=sys.stdin.readline
import heapq

N=int(readline())
A=list(map(int,readline().split()))
if N>=16:
    ans=(1<<16)-1
else:
    dp=[False]*(1<<16)
    dp[0]=True
    for a in A:
        prev=dp
        dp=[False]*(1<<16)
        for bit in range(1<<16):
            for i in range(16):
                dp[bit|a]|=prev[bit]
                a=a>>1|(a&1)<<15
    for ans in range((1<<16)-1,-1,-1):
        if dp[ans]:
            break
print(ans)