public class Factorial implements Runnable {
 private int n;
 
 public Factorial(int n) {
   this.n = n;
 }
 
 public int compute(int n) {
   // ... the code to compute factorials
 }
 
 public void run() {
   System.out.print("Factorial of " + String.valueOf(this.n) + ":")
   System.out.println(this.compute(this.n));
 }
 
 public static void main(String[] args) {
   Factorial f = new Factorial(25);
   Factorial g = new Factorial(10);
   Thread t1 = new Thread(f);
   Thread t2 = new Thread(f);
   t1.start();
   t2.start();
 }
}

//Another way of using the Runnable interface, which is even more succinct, is to use lambda expressions
public class Factorial {
 public int compute(int n) {
   // ... the code to compute factorials
 }
 
 public static void main(String[] args) {
   Factorial f = new Factorial();
 
   // the lambda function replacing the run method
   new Thread(() -> {
     System.out.println(f.compute(25));
   }).start();
 
   // the lambda function replacing the run method
   new Thread(() -> {
     System.out.println(f.compute(10));
   }).start();
 }
}