VBA Copying multiple Columns to 1 column??

Hello,
I have data in columns A-F and where the row ends in each column varies. what I would like to do is cut COlumns B & put into column A at the next available empty cell and continue for each column until it hits an empty column. I really don't want to specify Column F as ending because at times my data might go up to column M or Z, etc,. So, is there a way to to to move those columns all into column A at the next available empty cell in Col. A? I appreciate any help, I have looked around and can not find anything.

Example
A B C D E F
1 35 -50 -.545 101 1.025
4 95 -45 -.90 -25 2.5

Into this format
A
1
4
35
95
-50
-45
-.545
-.90
101
-25
1.025
2.5

Thanks