题目描述
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-----
3 1
ABC
-----Sample Output-----
aBC
输入格式
见题面
输出格式
见题面
样例输入
3 1
ABC
样例输出
aBC