#include <bits/stdc++.h>
using namespace std;
const int maxn=1e6+14;
long long n, sum = 0, minres = 0, ans = -1e18;
void solve(){
	cin >> n;
	for (int i = 1; i <= n; i++){
		int x;
		cin >> x;	
        minres = min(minres, sum);
		sum += x;
		ans = max(ans, sum - minres);
	}
	
	cout << ans;
}
int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);    cout.tie(0);
    if (fopen("input.txt","r")) {
        freopen("input.txt","r",stdin);
        freopen("output.txt","w",stdout);
    }
	solve();
	return 0;
}