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 <iostream>
#include <vector>

using namespace std;

int main(int argc, char* argv[]) {
  int N;
  cin >> N;
  
  vector<unsigned long long> A(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i];
  }

  unsigned long long min_dp;
  unsigned long long ans = 0;
  for (int i = 0; i < N; i++) {
    min_dp = A[i];
    ans += min_dp;
    for (int j = i+1; j < N; j++) {
      min_dp = min(min_dp, A[j]);
      ans += min_dp;
    }
  }

  cout << ans << endl;
  return 0;
}