#include<cstdio>
#include<algorithm>
using namespace std;
typedef long long LL;
const int L_N=2000+10;
int N,id[L_N],mt[L_N];
int main(){
	freopen("superbull.in","r",stdin);
	freopen("superbull.out","w",stdout);
	scanf("%d",&N);
	for(int i=1;i<=N;i++) scanf("%d",&id[i]);
	
	if(N==1){
		printf("0\n");
		return 0;
	}
	
	LL ans=0;
	for(int i=1;i<=N;i++){
		int mxi=0,mx=-1;
		for(int j=1;j<=N;j++)if(i!=j){
			if((id[i]^id[j])>mx){
				mx=id[i]^id[j];
				mxi=j;
			}
		}
		mt[i]=mxi;
		if(mt[mxi]!=i) ans+=id[i]^id[mxi]; 
	}
	printf("%lld\n",ans);
}