Smart solution by Oscar

Problem: 

I have table similar like this:

BatTodor

A 5
B 2
C 1
D 4
Is it possible with formula to generate list like this:
A
A
A
A
A
B
B
C
D
D
D
D

Solution

Array formula in cell A6:

=INDEX($A$1:$A$4,MATCH(FALSE, COUNTIF($A$5:A5,$A$1:$A$4)=$B$1:$B$4,0))

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