Problem:
Score : 400 points

Problem Statement

One day, Snuke was given a permutation of length N, a_1, a_2, ..., a_N, from his friend.

Find the following:

Constraints

1 ≦ N ≦ 200,000

(a_1, a_2, ..., a_N) is a permutation of (1, 2, ..., N).

Input

The input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the answer.

Note that the answer may not fit into a 32-bit integer.

Sample Input 1

3
2 1 3

Sample Output 1

9

Sample Input 2

4
1 3 2 4

Sample Output 2

19

Sample Input 3

8
5 4 8 1 2 6 7 3

Sample Output 3

85

Solution in C# (Mono 4.6.2.0) (judge verdict: Time Limit Exceeded)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;

class Program
{
    static void Main(string[] args)
    {
        int N = int.Parse(Console.ReadLine());
        int[] a = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
        long sum = 0;
        for (int i = 0; i < N; ++i)
        {
            int L = i;
            int R = i;
            for (L = i - 1; L >= 0 && a[L] > a[i]; --L) { }
            for (R = i + 1; R < N  && a[R] > a[i]; ++R) { }
            sum += Math.BigMul(i - L, R - i) * a[i];
        }
        Console.WriteLine(sum);
    }
}