import Control.Monad

import qualified Data.IntMap.Strict as IntMap

import Data.List.Split

import Data.Maybe

filterElements :: [Int] -> Int -> IntMap.IntMap Int -> [Int] -> [Int]

filterElements [] k counts reversedNums =

reverse $ filter (\num -> counts IntMap.! num >= k) reversedNums

filterElements (x : xs) k counts reversedNums = filterElements

xs

k

(IntMap.insertWith (+) x 1 counts)

(if isNothing $ IntMap.lookup x counts then x : reversedNums else reversedNums

)

lineToInts :: String -> [Int]

lineToInts s = map read $ splitOn " " s

main = do

t <- readLn :: IO Int

forM_ [1 .. t] $ \i -> do

params <- getLine

a <- getLine

let [n, k] = lineToInts params

result = filterElements (lineToInts a) k IntMap.empty []

putStrLn $ if null result then "-1" else unwords $ map show result