Reverse hlookup

[StephanS]

I have a table with headers in the first row and unique values that are listed in the rows under that header.
Now in another table I have listed all of these unique values and I want to show the corresponding header next to it.

Seems like a job for hlookup, but it can only find the unique values in the first row, the header, and return a certain row, so naturally it returns #NV. Is there a way to do it the other way around? Find the value in rows 2-x and return the header in row 1?

Example file attached. In Column F I’m looking for the formula. In Column G I’ve written the output I need.
example.ods

(I don’t care about the colors, they are just for easier identification)

[PKG]

Formula in F1:
=INDEX($A$1:$C$1,SUMPRODUCT(($A$2:$C$6=E1)*(COLUMN(A$1:C$1))))

1623242247551862.ods

[JohnSUN]

May be =IF(COUNTIF($A$2:$C$6;E1)=1; INDEX($A$1:$C$1;SUMPRODUCT(($A$2:$C$6=E1)*COLUMN($A$1:$C$1)));"Is missing or not unique!")

[StephanS]

Cool that works! Ingenious use of Sumproduct. Didn’t know such “smart uses” were possible with it. Gonna have to add that to my repertoire.

[anon73440385]

@StephanS

If the answer works for you, please consider to click the check mark () next to the answer. That’s the way to indicate a correct answer. Thanks in advance …

[StephanS]

oh sorry I didn’t realize there’s 2 possible interactions. I just upvoted before.