1) https://arena.olimpiici.com/#/catalog/84/problem/100186 -- eksk
2) https://codeforces.com/contest/2169/problem/E -- point selection
3) https://arena.olimpiici.com/#/catalog/462/problem/101252 -- paint
4) https://codeforces.com/problemset/problem/1132/F -- clear the string
5) https://cses.fi/problemset/task/1654 -- sos bit problem
6) https://codeforces.com/contest/1303/problem/E -- erase subsequence
7) https://codeforces.com/contest/1542/problem/D -- priority queue
8) https://atcoder.jp/contests/abc425/tasks/abc425_f -- inserting process
9) https://atcoder.jp/contests/abc450/tasks/abc450_f -- strongly connected 2
