n = read_line.to_i
xy = Array.new(n) { x, y = read_line.split.map &.to_i; {x, y} }
ans = xy.each_with_index.group_by { |(x, y), i|
  {x % 5, y % 9}
}.values.max_by(&.size).map { |(x, y), i|
  Tuple.new({x//5, y//9}, i)
}.group_by { |(x, y), i|
  (x + y) % 2
}.values.max_by(&.size).map { |xy, i| i + 1 }
puts ans.size, ans.join(' ')