#include <iostream>
using namespace std;

const int N = 1010;
int a[N];
int dp[N];

int main(){
    int n;
    cin >> n;
    for (int i = 1; i <= n; i ++ ){
        cin >> a[i];
        dp[i] = a[i];
    }

    for (int i = 1; i <= n; i ++ ){
        for (int j = 1; j < i; j ++ ){
            if(a[i] > a[j]){
                dp[i] = max(dp[i], dp[j]+a[i]);
            }
        }
    }

    int ans = a[1];
    for (int i = 1; i <= n; i ++ ){
        ans = max(ans, dp[i]);
    }
    cout << ans;

    return 0;
}