#include<iostream>
#define int long long
#define maxn 1000010
using namespace std;
namespace IO{
	int read()
	{
		int x=0,f=1;char ch=getchar();
		while(ch<'0'||ch>'9')
		{
			if(ch=='-')f=-1;
			ch=getchar();
		}
		while(ch>='0'&&ch<='9')
		{
			x=x*10+ch-'0';
			ch=getchar();
		}return x*f;
	}
	void print(int x)
	{
		if(x<0)
		{
			putchar('-');
			x=-x;
		}
		if(x>9)print(x/10);
		putchar(x%10+'0');
	}
}using namespace IO;
int n,a[maxn],f[maxn];
signed main()
{
//	freopen("rose4.in","r",stdin);
//	freopen("rose.out","w",stdout);
	n=read();
	for(int i=1;i<=n;i++)a[i]=read();
	for(int i=1;i<=n;i++)
	{
		for(int j=0;j<i;j++)
		{
			f[i]=max(f[i],f[j]+(a[i]&a[j]));
		}
	}print(f[n]);
	return 0;
}