10264 - The Most Potent Corner

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define endl '\n'
#define sz(x) int(x.size())
#define all(x) x.begin(), x.end()

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int n;
    while (scanf("%d", &n) != EOF) {
        int arr[(1 << n)];
        for (int i = 0; i < (1 << n); i++) {
            scanf("%d", &arr[i]);
        }
        vector<int> nums(1 << n);
        for (int i = 0; i < (1 << n); i++) {
            for (int j = 0; j < n; j++) {
                nums[i] += (arr[i ^ (1 << j)]);
            }
        }
        int Max = 0;
        for (int i = 0; i < (1 << n); i++) {
            for (int j = 0; j < n; j++) {
                Max = max(Max, nums[i] + nums[i ^ (1 << j)]);
            }
        }
        cout << Max << endl;
    }
}