#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int n;
const int MAX = 1e6+5;
int arr[MAX];
bool cmp(int a,int b){
    return a>b;
}
int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d",&arr[i]);
    sort(arr+1,arr+1+n,cmp);
    int maxx = -1;
    for(int i=1;i<n-1;i++){
        maxx = max(maxx,(arr[i]&arr[i+1]));
        maxx = max(maxx,(arr[i]&arr[i+2]));
    }
    cout<<maxx;
    return 0;
}

这也能过～～～～

数据一般呀