excel - Formula to list values not duplicating from two columns -

i have 2 columns values.

column1   column2           b b           e c           f d e f 

any way make forumla on separate column checks duplicates between columns 1 , 2, , lists values did not have duplicates?

like this:

column3 c d 

it can done array formula:

=iferror(index($a$1:index(a:a,match("zzz",a:a)),aggregate(15,6,(row($a$1:index(a:a,match("zzz",a:a)))-row($a$1)+1)/(countifs($b$1:index(b:b,match("zzz",b:b)),$a$1:index(a:a,match("zzz",a:a)))=0),row(1:1))),iferror(index($b$1:index(b:b,match("zzz",b:b)),aggregate(15,6,(row($b$1:index(b:b,match("zzz",b:b)))-row($b$1)+1)/(countifs($a$1:index(a:a,match("zzz",a:a)),$b$1:index(b:b,match("zzz",b:b)))=0),row(1:1)-sumproduct(1*(countifs($b$1:index(b:b,match("zzz",b:b)),$a$1:index(a:a,match("zzz",a:a)))=0)))),"")) 

put in c1 , copy down.

all $a$1:index(a:a,match("zzz",a:a)) setting extents of dataset. array formulas want limit number of iterations dataset.

the index(a:a,match("zzz",a:a)) returns last cell in column text in it.

if column numbers change "zzz" 1e+99.