How to simplify the circuit and calculate all currents in the resulting circuit using the loop current method?

Question

Electronics

There is a chain. How many nodes, branches and contours does it have? And how many will there be if E2, E3, E6 are removed from it?
I need to calculate all currents in a circuit without E2, E3, E6 using the loop current method. Can I count all J's as I's and just remove them from the circuit? Help me to understand! Thank you.
If I understand correctly, then there are 3 independent circuits?