The answer is 0.

**
This section requires Javascript.
**

You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.

Let’s take $p+1$ numbers made of 1s (1, 11, 111, ...) and their remainder modulo $p$ . For the Pigeonhole Principle, there are at least two of this numbers with the same remainder, so their difference will be a number made by 1s followed by 0s and multiple of $p$ whatever is $p$ .