Problem:
Score : 100 points

Problem Statement

You are given a string S of length N consisting of A, B and C, and an integer K which is between 1 and N (inclusive).
Print the string S after lowercasing the K-th character in it.

Constraints

1 ≤ N ≤ 50

1 ≤ K ≤ N

S is a string of length N consisting of A, B and C.

Input

Input is given from Standard Input in the following format:

N K
S

Output

Print the string S after lowercasing the K-th character in it.

Sample Input 1

3 1
ABC

Sample Output 1

aBC

Sample Input 2

4 3
CABA

Sample Output 2

CAbA

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

use text_io::*;
use std::collections::HashMap;
use std::process::exit;

fn main() {
    let mut a:usize = read!();
    let mut k:usize = read!();
    k -= 1;
    let mut s:String = read!();
    let mut v:Vec<char> = s.chars().collect();
    if v[k] == 'A' {
        v[k] = 'a';
    }
    else if v[k] == 'B' {
        v[k] = 'b';
    }
    else if v[k] == 'C' {
        v[k] = 'c';
    }
    let ss: String = v.into_iter().collect();
    println!("{}",ss);
}