import Data.Array.IO
import Control.Monad

slice n [] = []
slice n xs = take n xs : slice n (drop n xs)

main = do
  [n,k] <- map read . words <$> getLine :: IO [Int]

  let
    a = n `div` (k*k)
    b = n `mod` (k*k)
    c = head [x | x<-[0..k], x*x>=b]

    m = a*k+c

  ans <- newArray ((1,1),(m,m)) '.' :: IO (IOArray (Int,Int) Char)

  forM [0..a-1] $ \i -> do
    forM [1..k] $ \x -> do
      forM [1..k] $ \y -> do
        writeArray ans (i*k+x, i*k+y) '#'

  forM [0..b-1] $ \i -> do
    let
      x = a*k + i`mod`k+1
      y = a*k + i`div`k+1
    writeArray ans (x,y) '#'
  
  print m
  mapM_ putStrLn =<< slice m <$> getElems ans