import java.util.concurrent.locks.*;

class Banksystem4 {
    public static void main (String[] arg) {
        Bankkonto k = new Bankkonto();
        Thread ola = new Thread(new Kunde(k, "Ola"));
        Thread anne = new Thread(new Kunde(k, "Anne"));
        ola.start();  anne.start();
        try {
            ola.join();  anne.join();
        } catch (InterruptedException e) {}
        System.out.println("Kontoen er paa kr " + k.status());
    }
}

class Bankkonto {
    private int saldo = 0;
    Lock laas = new ReentrantLock(true);

    public void settInn (int kr) {
        laas.lock();
        try {
            int nySaldo = saldo + kr;
            saldo = nySaldo;
        } finally {
            laas.unlock();
        }
    }

    public int status () {
        return saldo;
    }
}

class Kunde implements Runnable {
    Bankkonto konto;
    String navn;

    Kunde (Bankkonto k, String n) {
        konto = k;  navn = n;
    }
    
    @Override
    public void run () {
        for (int i = 1;  i <= 1_000_000;  ++i)
            konto.settInn(1);
    }
}