Update your fork with MERGE (be sure you could do a merge)
git remote add upstream https://github.com/imitrichev/CPP_COURSE
git fetch upstream
git merge upstream/master
git push origin master
Update your fork with MERGE (be sure you could do a merge)
git remote add upstream https://github.com/imitrichev/CPP_COURSE
git fetch upstream
git merge upstream/master
git push origin master