import java.util.ArrayList;
import java.util.concurrent.locks.*;

public class Saksmonitor {
    private ArrayList<Saks> sakser = new ArrayList<>();
    private Lock laas = new ReentrantLock();

    public void settInn(Saks saks) {
        laas.lock();
        try {
            sakser.add(saks);
        } finally {
            laas.unlock();
        }
    }

    public int antallSakser() {
        laas.lock();
        try {
            return sakser.size();
        } finally {
            laas.unlock();
        }
    }
}