How to get unique value from two columns in a third colum

sorry,.....not getting... Is there something wrong

Thank you... Its working...however... sorry I forgot to add that I need all data from two columns including common value of both the columns in the third column but that common value should not be repeated in third column

ya.. you are right.. let me try

Its showing me the values those are common in both column... Instead of all values including common values.

I think... am not clear here... so elaborating more........

I have two colums let say A and B

A..... B
4..... 1
6..... 6
7..... 8
9..... 5
5..... 3

now we want result should be

C
4
6
7
9
5
1
8
3
Here in column c... we have value from col A and B . as column A already has 6 and 5 so these values are not added again in Column C .

Please let me know how can automate it in excel

Thank you.. Its working....

Also thanks for other two helpful links