Clever(1971)

Original title: Умница

The king married an intelligent and beautiful peasant girl, but he was not very smart himself, and his wife's superiority offended him. He sent his wife away, however, allowing her to take with her what she holds most dear. She gave the king a sleeping drink, and when he fell asleep, she took him to her hut: he was the most precious to her. Touched, the king returned his wife to the palace.