How to assign the last message of the vk_api user to a variable?

Question

Python

Hello, I am doing a training project for a bot in VK
. The essence of the error: (code on the screen) the num variable is not assigned a new message from the user, the request value is assigned (that is, request = num).
How to make the num variable be assigned a new message from the user following the message 'Enter a number to transfer to another CC'