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 Scala (2.11.7) (judge verdict: Accepted)

object Main {
  def main(args:Array[String]) = {
    val arr =  readLine.split(" ").map(_ .toInt)
    val out = readLine.split("").takeRight(arr(0))
    for (x <-0 until arr(0)){
      if (( x+1) == arr(1) ){
      	print(out(x)toLowerCase)
      }else{
        print(out(x))
      }  
    }
  }
}