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)

fn main() {
    let input: Vec<i32> = read_vec();
    let k = input[1];
    let p: Vec<i32> = read_vec();

    println!("{}", solve(&p, k));
}

fn read<T: std::str::FromStr>() -> T {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).ok();
    buf.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|s| s.parse().ok().unwrap())
        .collect()
}

fn solve(p: &[i32], k: i32) -> i32 {
    let mut prices = Vec::from(p);
    prices.sort();
    prices.iter().take(k as usize).sum()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_solve_1() {
        assert_eq!(210, solve(&[50, 100, 80, 120, 80], 3));
    }

    #[test]
    fn test_solve_2() {
        assert_eq!(1000, solve(&[1000], 1));
    }
}