The Great Telephone Robbery
Meshulam, a lowly bank clerk, has two hobbies: crime novels, and the ability to calculate investment interest in his head. When he learns of a local gang's plot to rob the bank, Meshulam realizes that this is his chance to make himself the hero of his own crime story -- by stopping them, in his own unique way!
Directors: Menahem Golan
Writers: Menahem Golan, Moshe Hadar
IMDB: tt0148846