I can't tell if the OP is serious or not.
Unless your dick is really really short, don't worry about increasing your dick length. Contrary to popular belief, a really long dick is pointless to have because most girls will never let you go in all the way. Hitting the cervix is not pleasurable for girls, it's actually quite painful. Penis girth is more important than length but even that doesn't make much of a difference.
The most important thing is to know how to use your dick.