The punch line of this joke.

An old man came to town for the first time. He remembers his daughter telling him that people in the city are called "public toilets", not "toilets". He wanted to go to the toilet but couldn't find it, so he asked for directions, but he forgot how to say it. He only remembers making phone calls in public places, not passers-by, which is very chaotic. What is a public place? The man pointed to a cinema, which should be a public place. . The old man walked to the door of the cinema and was about to go in. He was stopped by the ticket inspector in the cinema: "Your ticket?"

"Do you need a ticket to enter here?"

"Sure, please go there to buy tickets."

The old man thought, this city is just different. You have to buy tickets to go to the toilet. So I bought a ticket and went in. But he has never seen such a toilet. Looking around, the waiter found him a seat according to his ticket. The old man thought, after all, the city is the city, and you have to sit by the number when you go to the toilet. But he also found that there were many people in the cinema, including men and women with lights. He was puzzled and asked the people around him, "Are men and women together here?"

The man looked at him and said, "Yes".

He dared not ask more questions, thinking that since this is a rule, then don't violate it. "But why is the light still on?" .

"Turn off the lights when you leave."

"When will it start?"

"Start after the bell rings."

The old man finally understood. This time, it can be an eye-opener. People in this city should go to the toilet together and have their own places. But why do men and women have to turn off the lights before they start? He still doesn't understand. But the delay in ringing the bell made him very anxious.

Finally, the bell rang, the light went black, and what the old man had been holding back for a long time finally happened …

At this time, someone patted the old man on the shoulder, but the old man ignored him. After a while, the old man patted him again. The old man was a little unhappy and didn't reply kindly: "Mind your own business, what are you doing?"

The enthusiastic voice of the young man behind him: "Grandpa! ! Your baked sweet potato fell on my foot! !