nested IF formula with ISBLANK and MAX functions

Hi everyone. I am new on the forum. I searched and tried several formulas but without success, so hoping that you will be able to help me.

What I am trying to do is:
IF attempt 3 is blank; then check IF attempt 2 is blank ; then check if attempt 1 is blank, show “N/A”, else then Show attempt 1, else show attempt 2, else show attempt 3).

Second version is similar but has an added MAX function to show the final result, so:
IF attempt 3 is blank then check if attempt 2 is blank, if it is not blank, then take the max from attempt 3a and 3b; then check if attempt 2 is blank, if yes check if attempt 1 is blank, if not take the max from attempt 2a and 2b; then check if attempt 1 is blank, if yes, show "" (instead of 0), if not, then take max from attempt 1a and 1b.

I tried different versions of ISBLANK and NOT(ISBLANK). This is the last one that I came up with, but it says that there are too many arguments:

IF(ISBLANK(E2),C2,IF(ISBLANK(A2),"",MAX(A2,B2),IF(NOT(ISBLANK(C2),MAX(C2,D2),IF(NOT(ISBLANK(E2),MAX(E2,F2))))))

IFS(NOT(ISBLANK(A3),MAX(A3,B3),IF(NOT(ISBLANK(C3),MAX(C3,D3),IF(NOT(ISBLANK(E3),MAX(E3,F3),"")

where A2 is 1attemptA, B2 is 1attemptB, C2 and D2 are second attempt, and E2 and F2 are third attempt.

In the first formula I tried going backwards from third attempt to first and in the second from first to third.

Would appreciate any help. If something is not clear, please do tell.

Thank you!

Attaching a supporting document. Hope this helps. Added my comments in it. the formulas have no =, as all of them say that there are too many arguments.