Working hours calculation with 4 times

So I have this formula in F10 which calculates the working hours, everything fine, but I have an employee clocking in and out two times. How do I let it calculate the working hours in F10 in correspondance with AL4:7 ?
Id say just insert a line (no idea how to do this automatically) but then he still picks up the first 2 and not the last 2. Anyone a solution? Thanks!

gert.xlsm

Anyone knows an answer?