#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int n, k;
    cin >> n >> k;
    vector<int> v(n);
    string s;
    for (int i = 1; i <= n; i++) v[i-1] = i;
    cin >> s;
    while (s.size()){
        for (int i = 0; i < s.size() - 1; i++){
            if (s[i] == '(' && s[i+1] == ')'){
                if (v[i] == k){
                    cout << v[i+1] << endl;
                    return 0;
                } else if (v[i + 1] == k){
                    cout << v[i] << endl;
                    return 0;
                } else {
                    v.erase(v.begin()+i, v.begin()+i+2);
                    s.erase(s.begin()+i, s.begin()+i+2);
                    break;
                }
            }
        }
    }
}