#include <bits/stdc++.h>

typedef long double ld;
typedef long long ll;
using namespace std;
int di[] = {1, 0, -1, 0, 0, 1, -1, 1};
int dj[] = {0, 1, 0, -1, -1, 0, 1, -1};

const ll oo = 1e18;
const int N = 2e6 + 5, M = 1e4 + 5, MOD = 998244353;
#define EPS 1e-9

ll n, m, a[N], dp[N], lst[N], mx;

int main() {
    //ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    //memset(dp, -1, sizeof dp);
    cin >> n;
    for(int i=1;i <= n;i++){
        cin >> a[i];
        for(int j = 0; j < 40 ;++j){
            if(a[i] & (1 << j))
                dp[i] = max(dp[i] , dp[lst[j]] + (a[lst[j]] & a[i])),
                mx = max(mx, dp[i]);
        }
        for(int j = 0; j < 40 ;++j) {
            if (a[i] & (1 << j))
                lst[j] = i;
        }
    }
    cout << mx;
    return 0;
}