{-# Language StrictData, BangPatterns #-}
import Data.List
import qualified Data.Vector.Unboxed as U
import Control.Monad

data Fenwick = Leaf Int
             | Node Fenwick Int Int Fenwick
             deriving (Show, Eq)

create :: Int -> Fenwick
create 1 = Leaf 0
create n = Node (create $! n - 1) (2 ^ (n - 1)) 0 (create $! n - 1)

add :: Int -> Int -> Fenwick -> Fenwick
add _ x (Leaf y) = Leaf $! x + y
add i x (Node lch sz ps rch)
  | i == sz - 1 = Node lch sz (ps + x) rch
  | i < sz = Node (add i x lch) sz (ps + x) rch
  | otherwise = Node lch sz ps $! add (i - sz) x rch

binSearch :: Int -> Fenwick -> Int
binSearch = go 0
  where go !i rest (Leaf x)
          | x == rest = i
          | otherwise = i + 1
        go !i !rest (Node lch sz ps rch)
          | rest <= ps = go i rest lch
          | otherwise = go (i + sz) (rest - ps) rch

findNum :: Int -> U.Vector Int -> Int
findNum x v = go 0 (U.length v)
  where go !l !r
          | r - l == 1 = l
          | otherwise =
            let m = (l + r) `div` 2 in
            if v U.! m <= x then go m r else go l m

data Query = Add Int
           | Print
           deriving (Show, Eq)

parse s = case words s of
          [_, n] -> Add (read n)
          _ -> Print

collectValues :: [Query] -> U.Vector Int
collectValues = U.fromList . sort . foldl' iter []
  where iter !acc (Add v) = v : acc
        iter !acc _ = acc

main :: IO ()
main = do
  [q, k] <- mapM readIO . words =<< getLine
  qs <- replicateM q $ parse <$> getLine
  let vals = collectValues qs
      go :: [Query] -> Int -> Fenwick -> IO ()
      go [] _ _ = return ()
      go (Print : rest) !cnt !fwt
        | cnt < k = do
          print $ -1
          go rest cnt fwt
        | otherwise = do
          let index = binSearch k fwt
          print $! vals U.! index
          go rest (cnt - 1) (add index (-1) fwt)
      go (Add v : rest) !cnt !fwt =
          let index = findNum v vals in
            go rest (cnt + 1) (add index 1 fwt)
  go qs 0 $ create 18