import java.io.*; import java.util.*; import java.util.stream.*; public class Main { static int[] values; static int[][] dp; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = Math.min(sc.nextInt(), 16); values = new int[n]; for (int i = 0; i < n; i++) { values[i] = sc.nextInt(); } dp = new int[n][1 << 16]; System.out.println(dfw(n - 1, 0)); } static int dfw(int idx, int x) { if (idx < 0) { return x; } if (dp[idx][x] == 0) { for (int i = 0; i < 16; i++) { dp[idx][x] = Math.max(dp[idx][x], dfw(idx - 1, x | values[idx])); values[idx] = (values[idx] >> 1) | ((values[idx] % 2) << 15); } } return dp[idx][x]; } } class Utilities { static String arrayToLineString(Object[] arr) { return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n")); } static String arrayToLineString(int[] arr) { return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new)); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public int[] nextIntArray() throws Exception { return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray(); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }