问无法将存储库文件推送到远程存储库(GitHub)

EN

git remote add hacker https://github.com/xxx/HackerRank.git
git push hacker master

To https://github.com/xxx/HackerRank.git
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'https://github.com/xxx/HackerRank.git'
hint: Updates were rejected because the tip of your current branch is behind
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.

git pull hacker master
From https://github.com/xxx/HackerRank
 * branch            master     -> FETCH_HEAD
 * [new branch]      master     -> hacker/master
fatal: refusing to merge unrelated histories

$ git fetch hacker
From https://github.com/xxx/HackerRank
 * [new branch]      master     -> hacker/master

$ git merge hacker/master
fatal: refusing to merge unrelated histories