import Control.Monad
import Data.Function
import Data.Char
import Data.List
import Text.Read
import Text.ParserCombinators.ReadPrec

import qualified Data.ByteString.Char8 as B

newtype Pair a b = Pair { getPair :: (a, b) }

instance (Read a, Read b) => Read (Pair a b) where
  readPrec = Pair `dot` (,) <$> readPrec <* get <*> readPrec

instance (Show a, Show b) => Show (Pair a b) where
  show (Pair (a, b)) = show a ++ " " ++ show b

infixr 8 `dot`
dot :: (c -> d) -> (a -> b -> c) -> a -> b -> d
dot = ((.).(.))

main :: IO ()
main = do
  xs <- map read . words <$> getLine
  print $ solve xs

solve :: [Int] -> Int
solve = fst . head . filter (\(i, x) -> x == 0) . zip [1..]
