Can not install Nginx on CentOS 7.

Hello everybody, I installed Nginx on CentOS 7 by following link: https://www.digitalocean.com/community/tutorials/how-to-install-nginx-on-centos-7 [root@centos-512mb-nyc3-01 ~]# sudo yum install nginx But the system show errors: Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile

• base: centos.mirror.constant.com
• epel: ewr.edge.kernel.org
• extras: centos.mirror.constant.com
• updates: centos.mirror.constant.com Resolving Dependencies

Is this ok [y/d/N]: y Downloading packages: Failed to download prestodelta for repository updates: [Errno 5] [Errno 12] Cannot allocate memory Error downloading packages: 1:openssl-1.0.2k-16.el7_6.1.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-filesystem-1.12.2-2.el7.noarch: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-all-modules-1.12.2-2.el7.noarch: [Errno 5] [Errno 12] Cannot allocate memory 1:openssl-libs-1.0.2k-16.el7_6.1.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-mod-http-geoip-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-mod-stream-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-mod-http-xslt-filter-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-mod-http-image-filter-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-mod-mail-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory 1:nginx-mod-http-perl-1.12.2-2.el7.x86_64: [Errno 5] [Errno 12] Cannot allocate memory

What will I have to do now?