import Control.Applicative
import Data.Array
main = do
  [n,k] <- map read . words <$> getLine
  s <- getLine
  let a = array (1,n) $ fst $ foldl f ([],[]) $ zip s [1..]
      f (ar,st)   ('(',i) = (ar,i:st)
      f (ar,x:xs) (')',i) = ((i,x):(x,i):ar,xs)
  print $ a!k