{-# LANGUAGE BangPatterns #-}

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

import           Data.Array.IArray
import           Data.Array.IO
import           Data.Array.MArray
import           Data.Array.Unboxed
import           Data.Array.Unsafe

readi :: B.ByteString -> Int
readi b | Just (n, _) <- B.readInt b = n

prim :: Int -> UArray (Int, Int) Int -> [Int]
prim n g = go [1] []
  where
    go :: [Int] -> [Int] -> [Int]
    go !as !bs
        | null xs   = bs
        | otherwise = let (v, i) = minimum xs
                       in go (i:as) (v:bs)
      where
        xs =
            [ (g ! (a, i), i)
            | i <- filter (`notElem` as) [1 .. n]
            , a <- as
            , (g ! (a, i)) /= -1
            ]

main :: IO ()
main = do
    n <- readLn
    xss <- fmap (fmap readi . B.words) <$> replicateM n B.getLine
    a <- newArray ((1, 1), (n, n)) (-1) :: IO (IOUArray (Int, Int) Int)
    forM_ (zip [1 ..] xss) $ \(i, xs) -> do
        forM_ (zip [1 ..] xs) $ \(j, x) -> do
            writeArray a (i, j) x
    a <- unsafeFreeze a :: IO (UArray (Int, Int) Int)

    print . sum $ prim n a

