【Codeforces 611H】New Year and Forgotten Tree
【Codeforces 643G】Choosing Ads
【Codeforces 708D】Incorrect Flow
【Codeforces 587D】Duff in Mafia
【Codeforces 527E】Data Center Drama
【Codeforces 578F】Mirror Box
【Codeforces 568C】New Language
【Codeforces 704B】Ant Man
【Codeforces 521E】Cycling City
【Codeforces 566C】Logistical Questions
