import Control.Applicative ((<$>), (<*>))
import Control.Monad (guard)
import Data.Vector.Unboxed (Vector, (!), (//))
import qualified Data.Vector.Unboxed as V
import Data.Maybe (catMaybes)

main :: IO ()
main = solve <$> readLn <*> (V.fromList <$> map read <$> words <$> getLine) >>= putStrLn

solve :: Int -> Vector Int -> String
solve n ss = maybe "-1" (\(a, b, c) -> unwords . map show $ [a, b, c]) $ f n ss
  where f :: Int -> Vector Int -> Maybe (Int, Int, Int)
        f m v | null ls = Nothing
              | null rs = Nothing
              | otherwise = Just (head rs)
          where ls = do
                  i <- [0..m-3]
                  j <- [i+1..m-2]
                  k <- [j+1..m-1]
                  let ti = v ! i
                  let tj = v ! j
                  let tk = v ! k
                  guard $ ti > 0 && tj > 0 && tk > 0
                  guard $ ti /= tk && (ti - tj) * (tk - tj) > 0
                  return (i, j, k)
                rs = catMaybes $ do
                  (i, j, k) <- ls
                  let nv = v // [(i,0),(j,0),(k,0)]
                  case f m nv of
                   Nothing -> return $ Just (i, j, k)
                   Just _ -> return Nothing