Problem:
Score : 200 points

Problem Statement

A shop sells N kinds of fruits, Fruit 1, \ldots, N, at prices of p_1, \ldots, p_N yen per item, respectively. (Yen is the currency of Japan.)

Here, we will choose K kinds of fruits and buy one of each chosen kind. Find the minimum possible total price of those fruits.

Constraints

1 \leq K \leq N \leq 1000

1 \leq p_i \leq 1000

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N K
p_1 p_2 \ldots p_N

Output

Print an integer representing the minimum possible total price of fruits.

Sample Input 1

5 3
50 100 80 120 80

Sample Output 1

210

This shop sells Fruit 1, 2, 3, 4, and 5 for 50 yen, 100 yen, 80 yen, 120 yen, and 80 yen, respectively.

The minimum total price for three kinds of fruits is 50 + 80 + 80 = 210 yen when choosing Fruit 1, 3, and 5.

Sample Input 2

1 1
1000

Sample Output 2

1000

Solution in Rust (1.42.0) (judge verdict: Accepted)

use std::error::Error;
use std::io;

pub fn main() {
    if let Err(_e) = run() {
        panic!("failed.");
    }
}

fn run() -> Result<(), Box<dyn Error>> {
    let mut input = String::new();
    io::stdin().read_line(&mut input);
    let mut nk: Vec<i32> = input
        .trim()
        .split_whitespace()
        .map(|s| s.parse::<i32>().unwrap())
        .collect();
    let n = nk[0];
    let k = nk[1];
    input.clear();

    io::stdin().read_line(&mut input)?;
    let mut nums: Vec<i32> = input
        .trim()
        .split_whitespace()
        .map(|s| s.parse::<i32>().unwrap())
        .collect();
    input.clear();
    nums.sort();

    let mut result = 0;
    for i in 0..k {
        result += nums[i as usize];
    }
    println!("{}", result);

    Ok(())
}