|---------------------------------------------------------|
|---------------------------------------------------------|
|------------------------------7-7-7-7-7-7-(b9)(b9)(b9)(b9)(b9)(b9)(b9)-|
|------------------------------5-5-5-5-5-5-7-7-7-7-7-7-7--|
|-(b9)(b9)(b9)(b9)(b9)(b9)(b9)(b9)7-7-7-7-7-7-7---------------------------|
|-7-7-7-7-7-7-7-7-5-5-5-5-5-5-5---------------------------| x2