#include <bits/stdc++.h>
using namespace std;

// Returns the maximum sum obtainable by selecting any subset of elements
// while preserving the original order (i.e., a subsequence).
long long maxTreasure(const vector<int>& A) {
    long long sumPos = 0;
    int maxElem = INT_MIN;
    for (int v : A) {
        if (v > 0) sumPos += v;
        if (v > maxElem) maxElem = v;
    }
    if (A.empty()) return 0;               // no elements
    return (sumPos > 0) ? sumPos : maxElem; // choose positives or the largest (least negative) element
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N;
    if(!(cin>>N)) return 0;
    vector<int> A(N);
    for(int i=0;i<N;++i) cin>>A[i];
    cout<<maxTreasure(A);
    return 0;
}

import java.io.*;
import java.util.*;

public class Main {
    // Returns the maximum sum obtainable by selecting any subsequence of A.
    // If all numbers are non‑positive, returns the largest element.
    public static long maxTreasure(int[] A) {
        if (A.length == 0) return 0L;
        long sumPos = 0L;
        int maxElem = Integer.MIN_VALUE;
        for (int v : A) {
            if (v > 0) sumPos += v;
            if (v > maxElem) maxElem = v;
        }
        return (sumPos > 0) ? sumPos : maxElem;
    }

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();
        if (line == null || line.isEmpty()) return;
        int N = Integer.parseInt(line.trim());
        int[] A = new int[N];
        if (N > 0) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            for (int i = 0; i < N; i++) {
                A[i] = Integer.parseInt(st.nextToken());
            }
        }
        System.out.print(maxTreasure(A));
    }
}

def max_treasure(arr):
    """Return the maximum sum obtainable by selecting any subsequence of arr.
    If all numbers are non‑positive, the answer is the largest (least negative) element.
    An empty array yields 0.
    """
    if not arr:
        return 0
    sum_pos = sum(v for v in arr if v > 0)
    max_elem = max(arr)
    return sum_pos if sum_pos > 0 else max_elem

if __name__ == "__main__":
    import sys
    data = sys.stdin.read().strip().split()
    if data:
        n = int(data[0])
        arr = list(map(int, data[1:1+n]))
        print(max_treasure(arr))

// Returns the maximum sum obtainable by selecting any subset of elements
// while preserving the original order (i.e., a subsequence).
function maxTreasure(arr) {
    if (arr.length === 0) return 0;
    let sumPos = 0;
    let maxElem = -Infinity;
    for (const v of arr) {
        if (v > 0) sumPos += v;
        if (v > maxElem) maxElem = v;
    }
    return (sumPos > 0) ? sumPos : maxElem;
}

// Read input
const fs = require('fs');
const input = fs.readFileSync(0,'utf8').trim().split(/\s+/).map(Number);
let idx = 0;
const N = input[idx++]||0;
const arr = input.slice(idx, idx+N);
console.log(maxTreasure(arr));