import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) {
        
    //👾upper case to lowee case 
    
        Scanner sc =new Scanner(System.in);
        
        System.out.println("write ur name");
     String input = sc.nextLine();
          
   String a = input.toLowerCase();
     System.out.println(a);
   

 //👾replace space with underscore
 
    String a1 = input.replace(" ","_");

    System.out.println(a1);


//👾 replace name
  
  
     String num=   "dear name thanks a lot" ;

    String xv = num.replace("name","raju");

    System.out.println(xv);

 
 //👾 detect double and triple space in program

   String space= sc.nextLine();
   int detect = space.indexOf("  ");
 System.out.println("double space in "+detect+ "th character");

//👾 escape sequence character

 System.out.println("Dear harry thanks for this \n java course");






 }
}