E

#define _CRT_SECURE_NO_DEPRECATE

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>

#define ull unsigned long long
#define ll long long

using namespace std;

ll a[100001];
ll d[100001];

int main() {
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	d[0] = a[0];
	d[1] = a[1];
	ll mx = max(a[0], 0ll);
	for (int i = 2; i < n; i++) {
		d[i] = a[i] + mx;
		mx = max(mx, d[i - 1]);
	}
	mx = max(mx, d[n - 1]);
	cout << mx;


	return 0;
}