A B s 2
A D s 2
B C e 3
C G f 0
D E b 2
D F e 4
E H s 1
F K f 0
G I e 4
G J e 2
H K f 2
I L f 1
J L f 0
K L f 0
#define fs 0 f 
#define ss 1 s
#define sf 2 b
#define ff 3 e
