Below is an instruction that describes a task. Write a response that appropriately completes the request in French. Please answer in French.

### Instruction:
 Ashley had a birthday party and invited 20 of her friends, telling them to each invite one more person to attend the party. If half the number of the invited guests each came with one more person, what's the total number of people at the party, including Ashley?


### Response:
 Le nombre de personnes invitées est de 20 + 20 = 40.
Le nombre de personnes qui sont venues est de 40 / 2 = 20.
Le nombre total de personnes à la fête est Ashley + toutes les personnes qui sont venues, donc 1 + 20 = 21.