Putting things together: get letters from images Using what we have learnt above, write your code to save get the letters of all images. The letter-images are stored as 32 folders under folder extracted_letter_images.

For example, extracted_letter_images/A is a folder that saves all images of letter A. After you complete, each letter-folder should contain over 1000 letter-images.

Hint: (1) consider how to name different files in a letter-folder differently? (2) ingore those images with number of contours other than 4.