## 13. Friendly Lunch

Ten married couples, who were friends with each other, met to have lunch together. First, they had an aperitif in the living room, and then all twenty people followed each other into the dining room. What is the minimum number of people that must go into the dining room so that among them there are:

1) at least one married couple;
2) at least two people of the same gender?
13. It is clear that as soon as thirteen people enter the dining room, there will inevitably be at least one married couple among them.

As soon as three people enter the dining room, there will certainly be at least two people of the same gender among them.