Leo took a chocolate cake to his grandmother Rosa's ninetieth birthday party. It was in a black bag, and the party started at one o'clock. On the same tram sat Hana, who plays the tuba. Her tuba was in a black case, and her concert started at one o'clock too.
The tram was full, and both of them were on the phone. When they got off, each took the other's bag.
At half past twelve Hana opened her case and found a cake and a card: "For Rosa, 90 today. Call Leo." At the same time Leo opened his bag and found a tuba. They called each other and ran to the fountain. They changed bags, and at one o'clock both were in the right place. Rosa laughed: "Next year I want a tuba too!"
