import Control.Applicative
import Control.Monad
import qualified Data.ByteString.Char8 as B
import Data.Maybe (fromJust)
import Data.Array
import Text.Printf
import Debug.Trace
import qualified Data.Set as S

readInts :: B.ByteString -> [Int]
readInts = map (fst . fromJust . B.readInt) . B.words

getInts :: IO [Int]
getInts = liftM readInts B.getLine

getCol arr n m x = S.fromList [arr!(m,y,x) | y <- [1..n]]
getRow arr n m y = S.fromList [arr!(m,y,x) | x <- [1..n]]
getDiag arr n m = [S.fromList [arr!(m,i,i) | i <- [1..n]], S.fromList [arr!(m,n+1-i,i) | i <- [1..n]]]

calc ss n m1 m2 = minimum [S.size (S.union s1 s2) |
                           s1 <- ss!m1,
                           s2 <- ss!m2]

build arr n m = [(i,xs) | i <- [1..m],
                  let xs = [getCol arr n i x | x <- [1..n]]
                           ++ [getRow arr n i y | y <- [1..n]]
                           ++ getDiag arr n i]

main = do
  [n,m] <- getInts
  arr <- array ((1,1,1),(m,n,n)) <$> concat <$>
    forM [1..m] (\k -> concat <$>
                       forM [1..n] (\i -> zip [(k,i,j) | j <- [1..n]] <$> getInts))
  let ss = array (1,m) $ build arr n m
  let ans = minimum [calc ss n m1 m2 | m1 <- [1..m], m2 <- [m1+1..m]]
  print $ ans-1