Excel value from 2 neighbour columns

Hello to everyone! I have the following issue:
I have the following data:
Column A  Column B
1                  1
2                  3
3                  5
4                  11
5                  13

I need a way to automatically get the values from column A and column B into another column(ie., C) which will look like following:

Column C
1
1
2
3
3
5
4
11
5
13
P.S. Every value from column A is followed by the value from column B. Each value is located on the same row!