Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Click on the trophy icon in the top right corner of a challenge window to view a list of the top 10 challenge participants and the number of points they’ve resolved out of that challenge.
Public Domain.
