Facebook:
https://www.facebook.com/FUICPC
The Grades 1:
https://codeforces.com/group/c3FDl9EUi9/contest/262795/problem/J
Solution:
https://ideone.com/xKlWoZ
The Grades 2:
https://codeforces.com/group/c3FDl9EUi9/contest/263722/problem/C
Solution:
https://ideone.com/aJCE55
SORT2D - 2D-SORT:
https://www.spoj.com/problems/SORT2D/
Solution:
https://ideone.com/Ohis4j
