import java.io.PrintWriter
import java.util.*
import kotlin.math.*

fun PrintWriter.solve() {
    val n = nextInt()
    val a = Array(n) { nextInt() }
    val m = minOf(n, 16)
    val b = a.take(m)
    val set = mutableSetOf(0)
    fun shift(x: Int) = x / 2 + 32768 * (x % 2)
    for (entry in b) {
        var v = entry
        val setAdd = mutableSetOf<Int>()
        for (i in 0 until 16) {
            v = shift(v)
            for (w in set) {
                setAdd.add(v or w)
            }
        }
        for (add in setAdd) {
            set.add(add)
        }
    }
    println(set.maxOrNull())
}

fun main() {
    Thread(null, {
        val writer = PrintWriter(System.out, false)
        writer.solve()
        writer.flush()
    }, "solve", abs(1L.shl(26)))
        .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } }
        .apply { start() }.join()
}

// region Scanner
private var st = StringTokenizer("")
private val br = System.`in`.bufferedReader()

fun next(): String {
    while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())
    return st.nextToken()
}

fun nextInt() = next().toInt()
fun nextLong() = next().toLong()
fun nextLine() = br.readLine()
fun nextDouble() = next().toDouble()
// endregion