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++14 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

#define REP(i,s,n) for(int i=(int)(s);i<(int)(n);i++)

using namespace std;
typedef long long int ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef pair<int, int> PI;
const ll mod = 1e9 + 7;



int main(void){
  ll N;
  cin >> N;
  VL a(N+1,0);
  ll pohe;
  REP(i,1,N+1)
    {
      cin >> pohe;
      a[pohe] = i;
    }
  set<ll> bag;
  ll sum = 0;
  for (ll i = N; i >= 1; i--)
    { 
      ll index = a[i];
      bag.insert(index);
      ll l = index;
      while (l >= 1)
	{
	  l--;
	  if (bag.find(l) == bag.end())
	    break;
	}
      ll r = index;
      while (r <= N)
	{
	  r++;
	  if (bag.find(r) == bag.end())
	    break;
	}
      sum += i * (index - l) * (r - index);
    }
  cout << sum << endl;
}