#include<stdio.h>
#include<algorithm>
using namespace std;
int n,a[2005],key[2005];
long long ans;bool vis[2005];
void Prim(){
    for(int i=1,x=0;i<=n;i++,x=0){
        for(int j=1;j<=n;j++)
			if(!vis[j] && key[j]>=key[x])
            	x=j;
        vis[x]=true;
        for(int y=1;y<=n;y++)
            if(!vis[y])
				key[y]=max(key[y],a[x]^a[y]);
    }
}
int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    Prim();
    for(int i=1;i<=n;i++)ans+=(long long)key[i];
    printf("%lld",ans);
}