// Maximum satisfaction
#include <bitset>
int Solution::solve(vector<int> &a) {
    const int n = a.size();
    vector<int> bit(31);
    vector<bitset<100001>> st(31);
    for(int i=0;i<n;i++){
        for(int j=0;j<31;j++){
            if(a[i]&(1<<j)){
                bit[j]++;
                st[j].set(i);
            }
        }
    }

    int ans = 0;
    bitset<100001> curr;
    for(int i=0;i<n;i++) curr.set(i);
    for(int b = 30;b>=0;b--){
        if(bit[b]<4)
            continue;
        auto &now = st[b];
        auto temp = (curr&now);
        int cnt = temp.count();
        if(cnt>=4){
            ans+=(1<<b);
            curr = temp;
        }
    }
    return ans;
}