import java.util.regex.Matcher;
import java.util.regex.Pattern;

class Main {  
  public static void main(String args[]) {
    String original = "𝔍"; // "\uD835\uDD0D"
    
    Pattern p1 = Pattern.compile("\\p{L}");   // try regex without negation first
    Matcher m1 = p1.matcher(original);
    String r1 = m1.replaceAll("");
    System.out.println("r1: " + r1);
    System.out.println("r1 length: " + r1.length());
  
    Pattern p2 = Pattern.compile("\\P{L}");  // now try regex with negation
    Matcher m2 = p2.matcher(original);
    String r2 = m2.replaceAll("");
    System.out.println("r2: " + r2);
    System.out.println("r2 length: " + r2.length());
    System.out.println("r2 char(0): " + (int) r2.charAt(0));

    System.out.println("original: " + original);
  } 
}