How to Merge Two Column

[Sharad02]

Months	Month1	month2	month3
Jan-22	Jan-22	Jan-21	Jan-21
Feb-22	Jan-22	Feb-21	Jan-21
Feb-22	Feb-22	Feb-21	Feb-21
Mar-22	Jan-22	Mar-21	Jan-21
Mar-22	Feb-22	Mar-21	Feb-21
Mar-22	Mar-22	Mar-21	Mar-21

I want to Merge 1) Months and Month2 in one column ,2) Month1 and Month 3 in One column like Final Output should be like that 

Months	Month1
Jan-22	Jan-22
Feb-22	Jan-22
Feb-22	Feb-22
Mar-22	Jan-22
Mar-22	Feb-22
Mar-22	Mar-22
Jan-21	Jan-21
Feb-21	Jan-21
Feb-21	Feb-21
Mar-21	Jan-21
Mar-21	Feb-21
Mar-21	Mar-21

[Or · Accepted solution]

Your sample output doesn't match your description, but I'll answer the description and I'm sure you can adapt it if necessary.

Load Months, Month2 as Month1

From YourTable;

Concatenate

Load Month1 as Months, Month3 as Month1

From YourTable;