I tried to remove python3.6 by using this command sudo --purge configure python3.6
then after processing this code it seems all configurations were deleted. then after rebooting system my PC can not back to the desktop it returns to tty1 and can not install any dependencies and cannot update the system. When I try sudo apt-get update
When I tried to install sudo apt-get install VLC
I got this.
I can not back to ubuntu-desktop and even booting not work when I was booting and reached to Install Ubuntu it turns to a black screen.