import Data.Maybe
import Data.IORef
import qualified Data.ByteString.Char8 as B
import Control.Monad
import Control.Applicative

main :: IO ()
main = do
  rd <- intReader
  [q] <- rd 1
  replicateM_ q $ do
    [n] <- rd 1
    ps <- replicateM n ((\[x, y] -> (x, y)) <$> rd 2)
    putStrLn $ if ok ps then "YES" else "NO"

ok :: [(Int, Int)] -> Bool
ok ps = all check ps
  where
  x1 = minimum (map fst ps)
  x2 = maximum (map fst ps)
  y1 = minimum (map snd ps)
  y2 = maximum (map snd ps)
  check (x, y) = x == x1 || x == x2 || y == y1 || y == y2

intReader :: IO (Int -> IO [Int])
intReader = do
  ws <- fmap ((concatMap B.words) . B.lines) B.getContents >>= newIORef
  return $ \n -> do
    xs <- readIORef ws
    writeIORef ws (drop n xs)
    return (take n . map (fst . fromJust . B.readInt) $ xs)