$ git push -u origin master

To github.com:a653398363/testtest.git

 ! [rejected]        master -> master (fetch first)

error: failed to push some refs to 'git@github.com:a653398363/testtest.git'

hint: Updates were rejected because the remote contains work that you do

hint: not have locally. This is usually caused by another repository pushing

hint: to the same ref. You may want to first integrate the remote changes

hint: (e.g., 'git pull ...') before pushing again.

hint: See the 'Note about fast-forwards' in 'git push --help' for details.