With the input according to your example, i.e.
1 in cell A1
4 in cell B1
5 in cell A2
6 in cell B2
3 in cell A3
2 in cell B3
and the proposed formula, that is
=IF(ISERROR(MATCH(SMALL($A$1:$B$100,ROW()),A$1:A$100,0)),"",SMALL($A$1:$B$100,ROW()))
in cells C1 to C6 and
=IF(ISERROR(MATCH(SMALL($A$1:$B$100,ROW()),B$1:B$100,0)),"",SMALL($A$1:$B$100,ROW()))
in cells D1 to D6
what output do you get in these cells
C1: ???
D1: ???
C2: ???
D2: ???
C3: ???
D3: ???
C4: ???
D4: ???
C5: ???
D5: ???
C6: ???
D6: ???
Lars-Åke