#include<iostream>
#include<vector>
#include<cstdio>
using namespace std;

int main()
{
    int N, K, cnt = 0, result[10001];
    string str;
    vector<int> data;

    cin >> N >> K;
    cin >> str;
    for(int i=0; i<N; i++){
        if(str[i] == ')'){
            result[i + 1] = data.back();
            data.pop_back();
            result[result[i + 1]] = i + 1;
        }else data.push_back(i + 1);
    }
    cout << result[K] << endl;

    return 0;
}