If-then statement with multiple options

I have been working on an IF statement where there are multiple answers but I can't seem to get the formula to work. The If statement is going to look at two columns of data and should pull back the first NUMBER. Sometimes the first column will say "#N/A N/A" in which case the formula should look to the second column and pull that NUMBER. If both columns say "#N/A N/A" then I would like the answer to be "NR".

In another scenario I will have three columns of data. I would like the formula to pick up the first number in the columns no matter what follows. Again, if all three columns say "#N/A N/A" I would like the answer to be "NR".

I will attach to examples of what I am talking about. Here is the formula I have now but I can't seem to get it to work:

=IF(ISBLANK(B3),"",IF(D3="#N/A N/A",$D3,$D4))

Unfortunately, this formula isn't taking into account if D3 is actually a number. It also doesn't account for if both D3 and D4 are "#N/A N/A".

Any help would be greatly appreciated.

Thanks,

Example 1

Example 2