G-----------------------------------
D-----------------------------------
A---------22222222------------------
E-44444444--------22222222-00000-2-4   and keep repeating

Now, since it is so easy, you can make it more fun by adding octaves

G-----------4---4-----------------
D---6---6-----------4---4-2-2-2---
A---------2---2-------------------
E-4---4-----------2---2----0-0-2-4   and keep repeating

If thats too easy, than do this(^ means pull it down sortof)

G----------4-6^------------------
D---6---4------4---4---2-2-2-2---
A----6-4--2---------4-2----------
E-4--------------2--------0-0-2-4