给定程序的输出是什么？(     )

import java.io.*;
public class Test86 { 
    public static void main(String[] args) throws ClassNotFoundException, IOException {
        ByteArrayOutputStream bOut = new ByteArrayOutputStream(); 
        ObjectOutputStream objStrm = new ObjectOutputStream(bOut); 
        Beta b = new Beta() {
            { a=2; b=3; }
        }; 
        objStrm.writeObject(b); 
        ObjectInputStream objInStrm = new ObjectInputStream(new ByteArrayInputStream(bOut.toByteArray()));
        System.out.println(objInStrm.readObject().toString()); 
    } 
} 
class Alpha { 
    public int a; 
    public transient int b; 
} 
class Beta extends Alpha implements Serializable { 
    public String toString() { 
        return String.valueOf(a) + String.valueOf(b); 
    } 
}