Four boys met at a hotel in a resort town. They are representatives of different nationalities and religions, but they do not even think about it. Actually, why should they? It's so easy to be friends! They are interested to talk to each other, play on the beach, swim, and, of course, building a sand city. It could be destroyed very easily. But the boys do not worry about that. They keep the focus on the process of creation, not destruction. So every evening sea waves sweep the sand city away. And every morning boys rebuild the city again. But how long can they continue to do so in unison?