#include <iostream>
#include <algorithm>

using namespace std;

int main() {
    int n;
    cin >> n;

    int arr[n];
    for (int i = 0; i < n; ++i) {
        cin >> arr[i];
    }

    // Sort the array
    sort(arr, arr + n);

    int sum1 = 0, sum2 = 0;
    int finalSum = 0;
    if (n % 2 == 0) {
        // If n is even, take the last n / 2 elements
        for (int i = n - (n / 2); i < n; ++i) {
            if (sum1 + arr[i] > sum1) {
                sum1 += arr[i];
            } else {
                break;
            }
        }
        finalSum = sum1;
    } else {
        // If n is odd, calculate both sums
        for (int i = n - (((n - 1) / 2) + 1); i < n; ++i) {
            if (sum1 + arr[i] > sum1) {
                sum1 += arr[i];
            } else {
                break;
            }
        }
        for (int i = n - ((n - 1) / 2); i < n; ++i) {
            if (sum2 + arr[i] > sum2) {
                sum2 += arr[i];
            } else {
                break;
            }
        }
        // Output the largest sum
        finalSum = max(sum1, sum2);
    }

    // Check if the final sum is negative
    if (finalSum < 0) {
        finalSum = 0;
    }

    cout << finalSum << endl;

    return 0;
}