First I typed
sudo gedit /etc/apt/sources.list
after that I got one sources list then I typed
deb http://cran.rstudio.com/bin/linux/debian wheezy-cran3/
then I get the error like this
No command 'deb' found, did you mean:
Command 'derb' from package 'icu-devtools' (main)
Command 'deb3' from package 'quilt' (main)
Command 'debc' from package 'devscripts' (main)
Command 'dwb' from package 'dwb' (universe)
Command 'xdeb' from package 'xdeb' (universe)
Command 'debi' from package 'devscripts' (main)
Command 'dab' from package 'bsdgames' (universe)
deb: command not found
How should I proceed?