0
// s1 s2 s3 s4
C0: 1 2 3 0
C1: 1 0 1 1
C2: 2 3 2 2
0
// s1 s2 s3 s4
C0: 1 2 3 0
C1: 1 0 1 1
C2: 2 3 2 2