/* -*- coding: utf-8 -*-
 *
 * 2071.cc:  No.2071 Shift and OR - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000;
const int K = 16;
const int KBITS = 1 << K;

/* typedef */

/* global variables */

int as[MAX_N];
bool dp[K][KBITS];

/* subroutines */

inline int shift(int x, int l) {
  return ((x >> l) | (x << (K - l))) & (KBITS - 1);
}

/* main */

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", as + i);

  int m = 0;
  for (int i = 0; i < n; i++)
    if (as[i] > 0) as[m++] = as[i];
  if (m >= K) { printf("%d\n", KBITS - 1); return 0; }

  dp[0][0] = true;
  for (int i = 0; i < m; i++)
    for (int j = 0; j < KBITS; j++)
      if (dp[i][j]) {
	for (int l = 0; l < K; l++) {
	  int x = shift(as[i], l);
	  dp[i + 1][j | x] = true;
	}
      }

  for (int x = KBITS - 1; x >= 0; x--)
    if (dp[m][x]) { printf("%d\n", x); break; }

  return 0;
}