import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    

	public static void main(String[] args) throws Exception {
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(System.out));

		int size = Integer.parseInt(bufferedReader.readLine());
		Integer[] array = new Integer[size];
		String[] input = bufferedReader.readLine().split(" ");
		for (int i = 0; i < size; i++) {
			array[i] = Integer.parseInt(input[i]);
		}

		Integer[] transformedArray = getTransform(getTransform(array));
		long sum = 0;
		for (int element : transformedArray) {
			sum = sum + element;
		}
		bufferedWriter.write(sum + "\n");
		bufferedWriter.flush();
	}

	public static Integer[] getTransform(Integer[] array) {
		ArrayList<Integer> list = new ArrayList<Integer>();
		for (int k = 0; k < array.length; k++) {
			for (int i = 0; i < array.length - k; i++) {
				int j = i + k;
				list.add(findMax(array, i, j));
			}
		}
		return list.toArray(new Integer[list.size()]);
	}

	private static Integer findMax(Integer[] array, int i, int j) {
		int max = Integer.MIN_VALUE;
		for (int x = i; x <= j; x++) {
			max = Math.max(array[x], max);
		}
		return max;
	}


}