import Control.Applicative
import Control.Monad
import Data.List
import Data.Maybe

paren :: [Int] -> [(Char, Int)] -> [(Int, Int)]
paren (s : ss) [] = []
paren (s : ss) ((x, i) : xs)
    | x == '('  = paren (i : s : ss) xs
    | otherwise = (s, i) : paren ss xs

solve n k s = 
    if a == k then b else a
    where 
        (a, b) = fromJust . find (\ (a, b) -> a == k || b == k) . paren [-1] $ zip s [1 .. n]

main = do
    [n, k] <- map read . words <$> getLine :: IO [Int]
    s <- getLine
    print $ solve n k s