deb http://mirror.yandex.ru/debian/ stretch main
deb-src http://mirror.yandex.ru/debian/ stretch main

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

# stretch-updates, previously known as 'volatile'
deb http://mirror.yandex.ru/debian/ stretch-updates main
deb-src http://mirror.yandex.ru/debian/ stretch-updates main

deb http://httpredir.debian.org/debian/ stretch-backports main contrib non-free

deb http://ftp.debian.org/debian/ stretch-backports main