如何解决failed to push some refs to git

Administrator@PC-20150110FGWU /K/cocos2d/yc (master)

$ git push -u origin master

To [email protected]:yangchao0718/cocos2d.git

 ! [rejected]        master -> master (non-fast-forward)

error: failed to push some refs to '[email protected]:yangchao0718/cocos2d.git

hint: Updates were rejected because the tip of your current branch is behin

hint: its remote counterpart. Integrate the remote changes (e.g.

hint: 'git pull ...') before pushing again.

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