Create mex

[AbhiYMCA]

Fixes #{ISSUE_NUMBER}

• Pull Request Title is of form Problem Code (Contest Code) [Language].
• This problem already had an entry in this repository.
  • This solution is better than the one already in this repository.
• This solution is prepared by me and not copied from anywhere else on the web.
• I have added a copyright comment in my solution.
• I have updated README.md file (in appropriate order).
• I have read and followed Code Samples.
• I understand that pull request will be closed if I failed to update it even once in a week.

[aashutoshrathi]

Hi! Thanks for contributing to this repository.
Make sure you have checked points in PR correctly.