problem 4 done
Cleanup
Merge branch 'master' of https://github.com/nyucusp/gx5003-fall2013

# By enderfaruk (3) and Ender F Morgul (2)
# Via Ender F Morgul
* 'master' of https://github.com/nyucusp/gx5003-fall2013:
  update
  Delete problem3.py
  Delete problem3a.py
  update
  Delete problem2c.py