deb http://http.us.debian.org/debian stretch main contrib non-free
deb-src http://http.us.debian.org/debian stretch main contrib non-free

deb http://security.debian.org/ stretch/updates main contrib non-free
deb-src http://security.debian.org/ stretch/updates main contrib non-free

deb http://http.us.debian.org/debian stretch-updates main contrib non-free
deb-src http://http.us.debian.org/debian stretch-updates main contrib non-free

deb http://http.debian.net/debian stretch-backports main contrib non-free
deb-src http://http.debian.net/debian stretch-backports main contrib non-free