#include<iostream>
#include<cstdio>
using namespace std;
int a[1010];
int dp[1010];
int main() {
    int n;
    int answer;
    scanf("%d", &n);
    for (int i = 0 ; i < n ; ++i) {
        scanf("%d", &a[i]);
    }
    for (int i = 0 ; i < n ; ++i) {
        dp[i] = a[i];
        for (int j = 0 ; j < i; ++j) {
            if(a[i] > a[j]){
            dp[i] = max(dp[i], dp[j]+a[i]);
            }
        }
        answer = max(answer, dp[i]);
    }
    printf("%d\n", answer);
}