512
root: *noder1 *noder2 *noder3 *noder4 
noder1: *root *q1grad *q1grad *root
q1grad: *root *q1grad *q1grad 1
noder2: *q2grad *root *root *q2grad
q2grad: *q2grad *root 1 *q2grad
noder3: *q3grad *root *root *q3grad
q3grad: *q3grad 1 *root *q3grad
noder4: *root *q4grad *q4grad *root
q4grad: 1 *q4grad *q4grad *root