Ein dicker Hund (1982)

Eduard von Bittermagen and his friend Professor Pfiff, indulge in an amusing hobby. They take every opportunity to bet on anything. Their latest bet: Bittermagen claims that his nephew Tommi, a young rascal and the Professor's young daughter Julia will become a couple although the two are actually not crazy about each other. Of course, Pfiff bets against it. But then Bittermagen uses a macabre trick. He acts as if his last hour had come and summons Tommi and Julia to his "deathbed". He offers his immense heritage to both of them-if they solve a problem.