If and Countif

Hey guys,

If I have 2 columns in a table such as below and I want to query one of them to find out if a particular number is present I've figured out how to use IF/COUNTIF to do this. However, what I can't do is then get it to paste the corresponding value to the number (in the example below it'd be c).

Any ideas if I can do this with formulas?

Thanks!

=IF(COUNTIF(A1:A12,"3"),"???","MISSING")

ColumnA ColumnB
1 a
2 b
3 c
4 d
5 e
6 f
7 g
8 h
9 i
10 j
11 k
12 l