deb http://archive.ubuntu.com/ubuntu/ xenial main restricted universe deb-src http://archive.ubuntu.com/ubuntu/ xenial main restricted universe deb http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted universe deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted universe deb http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted deb-src http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted deb http://archive.ubuntu.com/ubuntu/ xenial-security main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ xenial-security main restricted universe multiverse