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 Rust (1.15.1) (judge verdict: Time Limit Exceeded)

use std::io::{self, Read,Error};
use std::u64;
use std::collections::HashMap;

fn main() {
    let mut buffer = String::new();
    if let Err(e) = io::stdin().read_line(&mut buffer) {
        println!("{}", e);
        return;
    }
    buffer = buffer.trim_right().to_string();

    let mut buffer = String::new();
    // read all values
    if let Err(e) = io::stdin().read_line(&mut buffer) {
        println!("{}", e);
        return;
    }
    let mut vals: Vec<u64> = buffer.split_whitespace().map(|v| v.parse::<u64>().unwrap()).collect();

    // 5 4 8 1 2 6 7 3
    let mut sum = 0;
    let n = vals.len();
    for l in 0..n {
        let mut min = vals[l];
        for r in l..n {
            let v = vals[r];
            if v < min {
                min = v;
            }
            sum = sum + min;
        }
    }
    println!("{}", sum);
}