Wrong directory part 1 lesson 3

Hej,
I have some problems with understanding why I cant get the right directory in my code.
This the error code.

I dont get why “1” is in - [Errno 2] No such file or directory: ‘/content/train_images/1.jpg’

This the code just before the error


And my files:

If needed I have a link to the colab browser, if the full code is needed.
https://colab.research.google.com/drive/1vBekZ4fIlHCvjz4R3qkuH9XBxlmlDffp

Hope you want to help, for I have no clue, how to get pass this problem.