import Control.Monad
import Data.Maybe
import qualified Data.ByteString.Char8 as BS
import Data.List

readInt = fst . fromJust . BS.readInt
readIntList = map readInt . BS.words
getInt = readInt <$> BS.getLine
getIntList = readIntList <$> BS.getLine

main = do
    [n,k] <- getIntList
    abs <- replicateM n $ do
        [a,b] <- getIntList
        return (a, b)
    let (as,bs) = unzip $ sort abs
    print . (as !!) . pred . length . takeWhile (<k) $ scanl' (+) 0 bs