intro(pre chorus):
E|------------------------------|
B|------------------------------|
G|------------------------------|
D 3-3-3-/-7-5-5-5-/-7-7-7-\-4-4-|  3x
A 5-5-5-/-5-3-3-3-/-5-5-5-\-2-2-|
E|------------------------------|

E|------------------------------|
B|------------------------------|
G|------------------------------|
D 5-5-5-5-/-7-(7)---------------|  1x ( ) means change from pre chorus to
A 3-3-3-3-/-5-(5)---------------|         chorus stroke as many times as
E|------------------------------|         needed (not fin yet)