
#include <iostream>
using namespace std;
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	
	int dp[1001] = { 0 };
	int A[1001] = { 0 };
	int n;
	cin >> n;
	for (int i = 0; i < n; i++)
		cin >> A[i];
	int max = A[0];
	dp[0] = A[0];
	for (int i = 1; i < n; i++) {
		dp[i] = A[i];
		for (int j = 0; j < i; j++) 
			if (A[i] > A[j] && dp[j] + A[i] > dp[i])
				dp[i] = dp[j] + A[i];
		if (max < dp[i]) max = dp[i];
	}
	cout << max;
	return 0;
}