#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

int main(void)
{
	int n, i, j, k, p = 0, q;
	scanf("%d", &n);
	int *arr = (int *)malloc(n*sizeof(int));
	for(i = 0; i < n; i++)
	{
		scanf("%d", &arr[i]);
	}
	int barr[1000];
	int carr[1000];
	//int sum = 0;
	for(k = 0; k < n; k++)
	{
		for(i = 0; i <= n - 1 - k; i++)
		{
			j = i + k;
			int max = INT_MIN;
			for(q = i; q <= j; q++)
			{
				if(arr[q] > max) max = arr[q];
			}
			barr[p] = max;
			p++;
		}
	}
	int t = 0, sum = 0;
	for(k = 0; k < p; k++)
	{
		for(i = 0; i <= p - 1 - k; i++)
		{
			j = i + k;
			int max = INT_MIN;
			for(q = i; q <= j; q++)
			{
				if(barr[q] > max) max = barr[q];
			}
			carr[t] = max;
			sum = sum + max;
			t++;
		}
	}
	printf("%d\n", sum);
	return 0;
}