A new computer science teacher came to our school.
By the end of the month, he taught us to check attendance:

Ping of Andrei!
Ping Oleg Olegovich.
Ping of Bears!
Ping Oleg Olegovich.
Ping wasin!
Ping Oleg Olegovich.

and so on.

Everything was fine, and then Ivanova became ill.

A call comes. All pinguined, came to Ivanova:
Ping Ivanova is!
There is no answer.
Ping Ivanova is!
There is no answer.
Ping Ivanova is!
There is no answer.

So is the whole lesson. Everyone left, a change began, and he stood in the passage and said:
Ping Ivanova is! Ping of Ivanova! Ping of Ivanova!

Then his doctors took him. No one has seen him again.