import Control.Monad

push :: Int -> [Int] -> Int -> [Int] -> Bool
push 0 _ _ ps = 2 `elem` ps 
push n bs b ps = let pushed = bs !! (b-1)
      in push (n-1) bs pushed (pushed:ps)

main :: IO ()
main = do
  n <- readLn :: IO Int
  bs <- replicateM n readLn :: IO [Int]
  print $ push n bs (head bs) []
