#include <cstdio>
#include <algorithm>
using namespace std;
int main() {
    int n, num = 0;
    int arr[2000] = {0};
    int arr2[2000] = {0};
    while (scanf("%d", &n) != EOF) {
        for (int i = 0; i < n; i++) {
            scanf("%d", &arr[i]);
        }
        for (int i = 0; i < n; i++) {
            arr2[i] = arr[i];
            for (int j = 0; j < i; j++) {
                if (arr[i] > arr[j]) {
                    arr2[i] = max(arr2[i], arr[i] + arr2[j]);
                }
                num = max(arr2[i], num);
            }

        }
        printf("%d", num);
    }

}