import Control.Applicative import Control.Monad import Data.Array import Data.Maybe import qualified Data.Set as S import qualified Data.ByteString.Char8 as B pqEmpty = S.empty pqAdd pq n = S.insert n pq pqGet pq = S.deleteFindMin pq pqMember pq n = S.member n pq pqNotMember pq n = S.notMember n pq pqIsEmpty pq = S.null pq pqSingleton n = S.singleton n hypot2:: Integer -> Integer -> Integer hypot2 x y = x*x+y*y solve :: Int -> [[Integer]] -> Integer solve n l = if ansd^2 < ans then ansd+10 else ansd where ansd = (*10) . ceiling . sqrt . (/100) . fromIntegral $ ans ans = primlike pqEmpty (pqSingleton (0,0)) 10 dst i = let [x1,y1] = la!i in map (\[x2,y2]->hypot2 (x1-x2) (y1-y2)) l la = listArray (0,n-1) l primlike visited pq mx | d==n-1 = max mx my | pqMember visited d = primlike visited gotpq mx | otherwise = primlike (pqAdd visited d) addedpq $ max mx my where addedpq = foldl pqAdd gotpq $ filter (pqNotMember visited . snd) $ zip (dst d) [0..] ((my,d),gotpq) = pqGet pq main = do n <- fst . fromJust . B.readInt <$> B.getLine l <- replicateM n $ map (fst . fromJust . B.readInteger) . B.words <$> B.getLine print $ solve n l