tasks w4 solving
4_4 solved
4_5 solved
4_6 last test case with no space around brackets still failing. 4_5 need to fix multithreading.
4_6 solved. Now refactoring is in process. Not finished yet. Build will failed
still refactoring 4_6
4_6 refactored and finished
4_5 to check
4_5 solved
refactored w_* solutions after Pavel's comments
4_* postrefactor polising
4_4 polished
Merge pull request #195 from ikolupaev/w4

W4 polished