7da xue zhang ju7    7xi zhu7          
80       80                             
808 0  80      808 0     80   80 80     
80 80 80  80     8 0           80       
80        80     80       8    0        
80         808 0         80             
8 0                80         8 0  80 80
                         80   80    8 0 
80  80 80  8    0       80 80        8  
8 0      80