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
pqIsEmpty pq    = S.null pq

hypot2:: Integer -> Integer -> Integer
hypot2 x y = x*x+y*y

solve :: Int -> [[Integer]] -> Integer
solve n l = adjust
  where
    adjust = if ansd*ansd < ans then ansd+10 else ansd
    ansd =  (*10) . ceiling . sqrt . (/100) . fromIntegral $ ans
    ans :: Integer
    ans = primlike pqEmpty (pqAdd pqEmpty (0,0)) 10
    dst:: Int -> [(Integer,Int)]
    dst i = let [x1,y1] = (la!i) in map (\(j,[x2,y2])->(hypot2 (x1-x2) (y1-y2),j)) $ zip [0..] l
    la = listArray (0,n-1) l
    primlike:: S.Set (Int) -> S.Set ((Integer,Int)) -> Integer -> Integer
    primlike visited pq mx
      | d==n-1       = max my mx
      | pqMember visited d = primlike visited nextpq mx
      | otherwise          = primlike (pqAdd visited d) (foldl pqAdd nextpq $ filter (not . pqMember visited . snd) (dst d)) $ max mx my
          where
            ((my,d),nextpq) = 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