#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>

typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;





int main()
{

    int Q;
    Q = 1;
    //cin >> Q;


    while (Q--) {
        int n, m;
        cin >> n >> m;
        string p;
        cin >> p;
        stack<int>a;
        vector<int>x(n + 2);
        for (int i = 0; i < n; i++) {
            if (p[i] == '(')a.push(i+1);
            else {
                x[i] = a.top(); x[a.top() - 1] = i + 1;
                a.pop();
            }
        }
        cout << x[m - 1];

    }
    return 0;
}