Problème d'installation des paquets

E: Entrée 1 mal formée dans list fichier /etc/apt/sources.list.d/yandex-browser.list ([option] not assignment)
E: La liste des sources ne peut être lue.
et voici le contenu du fichier: 


deb cdrom:[Xubuntu 18.04 LTS _Bionic Beaver_ - Release amd64 (20180426)]/ bionic main multiverse restricted universe

# See https://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://cm.archive.ubuntu.com/ubuntu/ bionic main restricted
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://cm.archive.ubuntu.com/ubuntu/ bionic-updates main restricted
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://cm.archive.ubuntu.com/ubuntu/ bionic universe
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic universe
deb http://cm.archive.ubuntu.com/ubuntu/ bionic-updates universe
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://cm.archive.ubuntu.com/ubuntu/ bionic multiverse
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic multiverse
deb http://cm.archive.ubuntu.com/ubuntu/ bionic-updates multiverse
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://cm.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
# deb-src http://cm.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu/ bionic partner
deb-src http://archive.canonical.com/ubuntu/ bionic partner

deb http://security.ubuntu.com/ubuntu/ bionic-security main restricted
# deb-src http://security.ubuntu.com/ubuntu/ bionic-security main restricted
deb http://security.ubuntu.com/ubuntu/ bionic-security universe
# deb-src http://security.ubuntu.com/ubuntu/ bionic-security universe
deb http://security.ubuntu.com/ubuntu/ bionic-security multiverse
# deb-src http://security.ubuntu.com/ubuntu/ bionic-security multiverse
 #### Manually Added sources ## source for libpng12-0 package deb http://mirrors.edge.kernel.org/ubuntu/ xenial main