Calculating total hours based on logs

Hello,

I have a set of data for a entry system where we swipe in and out of the office. What i am trying to get is the total time that people are at the office for on each day. The issue i come into is when someone comes into work then leaves for lunch then comes back in then leaves for the day. (Yellow Highlighting).

Could anyone help me at getting the Total hours that people where at the office for?

Thankss