Solution #1:
  s0  = 4 :: Word8
  s1  = 6 :: Word8
  s2  = 4 :: Word8
  s3  = 0 :: Word8
  s4  = 2 :: Word8
  s5  = 6 :: Word8
  s6  = 1 :: Word8
  s7  = 5 :: Word8
  s8  = 7 :: Word8
  s9  = 1 :: Word8
  s10 = 8 :: Word8
  s11 = 4 :: Word8
  s12 = 9 :: Word8
  s13 = 5 :: Word8
  s14 = 3 :: Word8
  s15 = 3 :: Word8
This is the only solution.