http://codeforces.com/contest/55/problem/C (4) //[NICE] Size of piece from border↵↵http://codeforces.com/problemset/problem/255/E --MEX↵↵https://devskill.com/CodingProblems/ViewProblem/91↵↵https://devskill.com/CodingProblems/ViewProblem/364↵↵Project Euler #96: Su ...