   1  0     0
   2  1     0
   3  2     0
   4  3     0
   5  0     1
   6  1     1
   7  2     1
   8  3     1
   9  0    10
  10  1    10
  11  2    10
  12  3    10
  13  0    11
  14  1    11
  15  2    11
  16  3    11
