#include<iostream>

#include<cstdio>

#include<cstring>

#include<string>

#include<algorithm>

#include<cctype>

#include<cmath>

#include<cstdlib>

#include<queue>

#include<ctime>

#include<vector>

#include<set>

#include<map>

#include<stack>

using namespace std;

long long a[],n,Ans,belong[];

inline bool cmp(long long x,long long y){return x>y;}

inline void work(){

    long long i,j,k;

    for(i=;i<=n;i++){

      k=a[i];

      for(j=;j>=;j--)

        if((<<j)&a[i]){

          if(!belong[j]){

              belong[j]=a[i];

              break;

          }

          a[i]^=belong[j];

        }

      if(!a[i])Ans+=k;

    }

}

int main(){

    long long i,j,k;

    scanf("%lld",&n);

    for(i=;i<=n;i++)scanf("%lld",&a[i]);

    sort(a+,a+n+,cmp);

    work();

    printf("%lld\n",Ans);

    return ;

}