How to request a number through cin in C++ so that it ends with the number 5?

Question

C++ / C#

I understand that the question is the dumbest, but I did not find a solution on the Internet (I would like to see the code as an answer)

Answer 1

This is impossible, the man is free to enter anything into the console.
But your task as a programmer is to somehow prevent incorrect input. Whether to display an error, or independently round, or require re-entry ... You yourself think what is required from your program.
The condition "ends in 5" is equivalent to "not divisible by 10, but divisible by 5".