using System;
using System.Linq;
class Program
{
    static void Main(string[] args)
    {
        string[] str = Console.ReadLine().Split(' ');
        string text=  Console.ReadLine();
        Palen Ans = new Palen(int.Parse(str[0]), text);
        Ans.calc();
        Console.WriteLine(Ans.Ans(int.Parse(str[1])).ToString());
        Console.ReadLine();

    }
    class Palen {
        string Str = String.Empty;
        int[,] AnsPair;
        int PairCount=0;
        int[] StrIndex;

        public Palen(int StrLength,string ininput) {
            Str = ininput;
            AnsPair = new int[2,StrLength / 2];
            StrIndex = new int[StrLength];
            StrIndex = StrIndex.Select((x, index) => x = index+1).ToArray();
        }
        public void calc() {
            while (Str!="") {
                int IndexPair = Str.IndexOf("()");
                AnsPair[0, PairCount] = StrIndex[IndexPair];
                AnsPair[1, PairCount] = StrIndex[IndexPair + 1];
                Str = Str.Substring(0, IndexPair) + Str.Substring(IndexPair + 2);//Str.Length-1
                int[] NewStrIndex = new int[StrIndex.Length - 2];
                for (int Loop1 = 0; Loop1 < NewStrIndex.Length; Loop1++) {
                    NewStrIndex[Loop1] = Loop1 < IndexPair ? StrIndex[Loop1] : StrIndex[Loop1 + 2];
                }
                StrIndex = NewStrIndex;
                PairCount++;
            }
        }
        public int Ans(int inIndex) {
            for (int Loop1 = 0; Loop1 < AnsPair.GetLength(1); Loop1++)
            {
                if (inIndex == AnsPair[0,Loop1]) {
                    return AnsPair[1, Loop1];
                }
                if (inIndex == AnsPair[1, Loop1])
                {
                    return AnsPair[0, Loop1];
                }
            }
            return -1;
        }
    }
}