import Control.Monad
import Data.List (foldl', findIndex, unfoldr)

replace i xs = xs1 ++ (xj : xi : xs2)
 where (xs1,(xi:xj:xs2)) = splitAt (i-2) xs

main = do
 n <- readLn
 k <- readLn
 is <- map (read . head . words) <$> replicateM k getLine
 goal <- map read . words <$> getLine
 let start = amida [1..n] is
 let inss = unfoldr (insert goal) start
 print (length inss)
 putStr $ (unlines . map (unwords . map show)) inss

amida :: [Int] -> [Int] -> [Int]
amida xs = foldl' (flip replace) xs

insert :: [Int] -> [Int] -> Maybe ([Int],[Int])
insert goal xs = do
 guard (goal /= xs)
 let xi = fst $ head $ dropWhile (uncurry (==)) $ zip goal xs
 i <- succ <$> findIndex (==xi) xs 
 let ji = [i-1,i]
 return (ji, replace i xs)