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 str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   }
} import java.util.*; util.* java public class Main{
   public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     int N = sc.nextInt();
     int K = sc.nextInt();
     String str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   }
} Main public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     int N = sc.nextInt();
     int K = sc.nextInt();
     String str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   } main {
     Scanner sc = new Scanner(System.in);
     int N = sc.nextInt();
     int K = sc.nextInt();
     String str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int K = sc.nextInt(); K sc.nextInt() sc.nextInt sc String str = sc.next(); str sc.next() sc.next sc String[] s = new String[N]; s new String[N] N String ans =""; ans "" String[] strArraySub = str.split(""); strArraySub str.split("") str.split str "" String A = "A" A "A" B = "B" B "B" C = "C"; C "C" String[] strArray = new String[str.length()]; strArray new String[str.length()] str.length() str.length str for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     } int i = 1; int i = 1; i 1 i < strArraySub.length i strArraySub.length strArraySub strArraySub.length i++ i++ i {
      strArray[i - 1] = strArraySub[i];
     } {
      strArray[i - 1] = strArraySub[i];
     } strArray[i - 1] = strArraySub[i] strArray[i - 1] strArray i - 1 i 1 strArraySub[i] strArraySub i if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         } strArraySub[K-1].equals(A) strArraySub[K-1].equals strArraySub[K-1] strArraySub K-1 K 1 A {
            strArraySub[K-1] ="a";
         } strArraySub[K-1] ="a" strArraySub[K-1] strArraySub K-1 K 1 "a" if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         } strArraySub[K-1].equals(B) strArraySub[K-1].equals strArraySub[K-1] strArraySub K-1 K 1 B {
            strArraySub[K-1] ="b";
         } strArraySub[K-1] ="b" strArraySub[K-1] strArraySub K-1 K 1 "b" if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         } strArraySub[K-1].equals(C) strArraySub[K-1].equals strArraySub[K-1] strArraySub K-1 K 1 C {
            strArraySub[K-1] = "c";
         } strArraySub[K-1] = "c" strArraySub[K-1] strArraySub K-1 K 1 "c" {
           strArraySub[K-1] = "e";
         } strArraySub[K-1] = "e" strArraySub[K-1] strArraySub K-1 K 1 "e" for(int j =0;j<N;j++){
       ans += strArraySub[j];
     } int j =0; int j =0; j 0 j<N j N j++ j++ j {
       ans += strArraySub[j];
     } {
       ans += strArraySub[j];
     } ans += strArraySub[j] ans strArraySub[j] strArraySub j System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
   public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     int N = sc.nextInt();
     int K = sc.nextInt();
     String str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   }
} public class Main{
   public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     int N = sc.nextInt();
     int K = sc.nextInt();
     String str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   }
} Main
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 str = sc.next();
     String[] s = new String[N];
     String ans ="";
     String[] strArraySub = str.split("");
     String A = "A", B = "B",C = "C";
     String[] strArray = new String[str.length()];

     for (int i = 1; i < strArraySub.length; i++) {
      strArray[i - 1] = strArraySub[i];
     }
          if(strArraySub[K-1].equals(A)){
            strArraySub[K-1] ="a";
         }else if(strArraySub[K-1].equals(B)){
            strArraySub[K-1] ="b";
         }else if(strArraySub[K-1].equals(C)){
            strArraySub[K-1] = "c";
         }else{
           strArraySub[K-1] = "e";
         }

     for(int j =0;j<N;j++){
       ans += strArraySub[j];
     }
     System.out.println(ans);
   }
}
