error in challenge question. hashset

Question

What is output of this code? Sololearn give right answer , that size of set is 5. But, if I'm not mistaken, right answer is 6. I'm interesting your opinion.
https://code.sololearn.com/cc2zV5cYcp6e/?ref=app

Answer 1

Kirill the code you attached gives answer 6.
So how 5 ??

Answer 2

Kirill Which question are you talking about ??

Answer 3

Kirill where sololearn gave answer 5 ??

Answer 4

Kirill You can attach the challenge question

Answer 5

edited post.

Answer 6

I have screen. it was question in challenge

Answer 7

I can send screenshots with answer of sololearn