import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) {
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        try {
            int T = 1;
            for (int i = 0; i < T; ++i) {
                Runner runner = new Runner(br, bw);
                runner.run();
                runner.flush();
            }
            br.close();
            bw.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

class Solution {
    final int N;
    final int[] numbers;

    public Solution(int N, int[] number) {
        this.N = N;
        this.numbers = number;
    }

    public int solution() {
        int[] dp = new int[N]; // 자신이 마지막 원소인 부분 수열의 최대 합
        for (int i = 0; i < N; ++i)
            dp[i] = numbers[i];

        // DP 계산
        for (int i = 1; i < N; ++i) {
            int curNum = numbers[i];
            for (int j = 0; j < i; ++j) {
                int prevNum = numbers[j];
                if (prevNum < curNum) {
                    dp[i] = Math.max(dp[i], dp[j] + curNum);
                }
            }
        }

        int res = Integer.MIN_VALUE;
        for (int i = 0; i < N; i++) {
            res = Math.max(res, dp[i]);
        }
        return res;
    }
}

class Runner  {
    final Reader reader;
    final BufferedWriter bw;

    final int N;
    final int[] numbers;

    Runner(BufferedReader br, BufferedWriter bw) {
        this.reader = new Reader(br);
        this.bw = bw;
        try {
            this.N = Integer.parseInt(br.readLine());
            this.numbers = reader.readInts();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public void flush() {
        try {
            bw.write('\n');
            bw.flush();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public void run() throws IOException {
        var sol = new Solution(N, numbers);
        var res = sol.solution();
        bw.write(String.valueOf(res));
    }
}

class Reader {
    private BufferedReader br;

    public Reader(BufferedReader br) {
        this.br = br;
    }

    public int[] readInts() throws IOException {
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int cnt = st.countTokens();
        int[] ints = new int[cnt];
        for (int i = 0; i < cnt; ++i) {
            ints[i] = Integer.parseInt(st.nextToken());
        }
        return ints;
    }
}