import Control.Applicative

solve [] _ = 0
solve (x:xs) n
  | x == n = solve xs (n-1)
  | otherwise = 1 + solve xs n

main :: IO()
main = do
  n <- (read::String->Int) <$> getLine
  a <- reverse . map (read::String->Int) . words <$> getLine
  print $ solve a n