n = read_line.to_i
a = read_line.split.map(&.to_i64).sort
b = read_line.split.map(&.to_i64).sort
left = Array.new(n, 0i64)
right = Array.new(n, 0i64)
(n - 1).times do |i|
  left[i + 1] = left[i] + (a[i] - b[i]).abs
  right[i + 1] = right[i] + (a[-1 - i] - b[-1 - i]).abs
end
s = n.times.min_of { |i| left[i] + right[n - 1 - i] }
ans = n.times.select { |i| left[i] + right[n - 1 - i] == s }.map { |i| a[i] }.to_a.uniq
puts ans.size
puts ans.join(" ")