import Control.Monad
import Data.List

rInteger :: String -> Integer
rInteger = read

solve :: [[Integer]] -> Integer
solve (_:[]) = 0
solve xs = iter (head xs) xs + solve (tail xs) where
    iter _ [] = 0
    iter x (y:ys) | c1 && c2    = 1 + iter x ys
                  | otherwise   = iter x ys
                  where
                    b1 = last x
                    c1 = b1 > head y
                    c2 = b1 < last y

main = do
    [n, m] <- map read . words <$> getLine
    ls <- sort . map (\ [x, y] -> if x > y then [y, x] else [x, y]) . map (map rInteger . words) <$> replicateM n getLine
    print $ solve ls