Really stuck and lucking for some help.

I have a spread sheet I use for tracking project man-hours by week by sub project task, Weeks are listed across row 1, projects are listed down column A and sub projects down column B.

What I would like to do is enter a week and a project input and for the formula to the search based on two criteria a column based on a week number and multiple rows based on a project number and then sum the results,

If I've attached this sample picture correctly you can see what I mean , the answer should be 19.

Sample.jpg