import java.util.*;
public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      int n = sc.nextInt();
      int k = sc.nextInt();
      String s = sc.next();
      int len = n - k + 1;
      String str1 = s.substring(0, k-1);
      String str2 = s.substring(k-1, n);
      System.out.println(str2 + str1);
  }
}