#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1010;
int w[N], d[N];
int main()
{
int n;
cin >> n;
for (int i = 1; i <= n; i++) cin >> w[i];
int ans = 0;
for (int i = 1; i <= n; i++)
{
d[i] = w[i];
for (int j = 1; j < i; j++)
if (w[i] > w[j])
d[i] = max(d[i], d[j] + w[i]);
ans = max(ans, d[i]);
}
cout << ans << "\n";
return 0;
}