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