#include <iostream>
#include <string>
using namespace std;
int a[10000];

int main() {
  int n, k;
  string s;
  cin >> n >> k >> s;
  for (size_t i = 0; i < s.length(); i++) {
    if (s[i] == '(') {
      int cnt = 1;
      for (size_t j = i + 1; j < s.length(); j++) {
        if (s[j] == '(') {
          cnt++;
        } else {
          if (!a[j]) {
            cnt--;
            if (!cnt) {
              a[i] = j;
              a[j] = i;
              break;
            }
          }
        }
      }
    }
  }
  cout << a[k - 1] + 1 << endl;
}