the output proves

What output? Do you think you're that important that the dozens of people reading your post should cut and paste your code and run it to see the output, instead of you spending two seconds actually posting the output?

The explanation has already been posted, but for everyone reading this: if you're going to post code, and its output matters, post the output as well. Don't expect everyone to either magically deduce what the output will be, or to copy, paste and run it.