The summary of 3 chapters for linux basics => https://drive.google.com/file/d/1cbAWePRVie-npaMAl32BsTPnyP42VNDW/view?usp=sharing
Problem 1 (Bear and Big brother) => https://codeforces.com/contest/791/submission/61366219
Problem 2 (Mishka and contest) => https://codeforces.com/contest/999/submission/102158774