#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int get_max_sum(const vector<int>& vec) {
    vector<int> max_sums(vec.size());
    max_sums[0] = vec[0];
    for (int i = 1; i < vec.size(); i++) {
        int max_sum = 0;
        for (int j = 0; j < i; j++) {
            if (vec[j] < vec[i]) {
                max_sum = max(max_sum, max_sums[j]);
            }
        }
        max_sums[i] = max_sum + vec[i];
    }
    return *max_element(max_sums.begin(), max_sums.end());
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int numbers_amount;
    cin >> numbers_amount;
    vector<int> numbers(numbers_amount);
    for (int i = 0; i < numbers_amount; i++) {
        cin >> numbers[i];
    }
    cout << get_max_sum(numbers) << endl;

    return 0;
}