public class Main {
    public static void main(String[] args) {
        Thread powThread = new Thread(() -> pow());
        powThread.start();
        fib();
    }

    public static void pow() {
        try {
            int fir = 1;
            System.out.println("P: " + fir);

            Thread.sleep(1000);

            while(true) {
                fir *= 2;
                System.out.println("P: " + fir);

                Thread.sleep(1000);
            }
        } catch(InterruptedException e) { }
    }

    public static void fib() {
        try {
            int fir = 0;
            int sec = 1;

            System.out.println("F: " + fir);

            Thread.sleep(1000);

            System.out.println("F: " + sec);

            Thread.sleep(1000);

            while(true) {
                System.out.println("F: " + (fir + sec));
                sec += fir;
                fir = sec - fir;

                Thread.sleep(1000);
            }
        } catch(InterruptedException ex) { }
    }
}