N, K = gets.split.map(&:to_i)
s = 1

while s * s < N || s * K < N
  s += 1
end

G = Array.new(s) { Array.new(s, '.') }
cy = 0
cx = 0

N.times do
  if G[cy][cx] == '#'
    cx += 1
  end

  G[cy][cx] = '#'
  cy += 1
  cx += 1

  cy %= s
  cx %= s
end

puts s
puts G.map { |row| row.join }