Using IF, INDEX and MATCH to retrive the value out of the two column that is not blank

I want to use IF, INDEX and MATCH function together to get the output from the another sheet that has two columns (one of them in always blank and so need value from a column which in not blank) !!

The formula I'm using looks like :-

=IF(ISBLANK('DATA 1'!B:B);INDEX('DATA 1'!B:B;MATCH(OUTPUT!B14;'DATA 1'!A:A;0));INDEX('DATA 1'!C:C;MATCH(OUTPUT!B14;'DATA 1'!A:A;0)))

This formula is returning values from one column only and when the corresponding column is blank it shows #N/A .
I want it to show the value from whichever clolumn (out of the two on another sheet) that is not blank.
Thanks in advance!