package main

import "fmt"

func shift(a int) int {
	return (1<<15)*(a%2) + (a / 2)
}

func main() {
	var n int
	fmt.Scanln(&n)
	a := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
	}
	if n >= 16 {
		fmt.Println((1 << 16) - 1)
		return
	}
	dp := make([]bool, 1<<16)
	x := a[0]
	for j := 0; j < 16; j++ {
		dp[x] = true
		x = shift(x)
	}
	for i := 1; i < n; i++ {
		x = a[i]
		temp := make([]bool, 1<<16)
		for j := 0; j < 16; j++ {
			for k := 0; k < (1 << 16); k++ {
				if dp[k] {
					temp[k^x] = true
				}
			}
			x = shift(x)
		}
		dp = temp
	}
	max := 0
	for k := 0; k < (1 << 16); k++ {
		if dp[k] && (k > max) {
			max = k
		}
	}
	fmt.Println(max)
}