#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <cctype>
#include <tuple>
#include <climits>
#include <bitset>
#include <cassert>
#include <random>

#ifdef _MSC_VER
#include <agents.h>
#endif

#define FOR(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define REV(v) v.rbegin(), v.rend()
#define MEMSET(v, s) memset(v, s, sizeof(v))
#define UNIQUE(v) (v).erase(unique(ALL(v)), (v).end())
#define MP make_pair
#define MT make_tuple

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n, k;
	cin >> n >> k;
	
	string s;
	cin >> s;

	stack<int> st;
	int match[10101];
	rep(i, s.size()){
		if (s[i] == '(') st.push(i);
		else{
			int x = st.top();
			st.pop();
			match[x] = i;
			match[i] = x;
		}
	}

	cout << match[k - 1] + 1 << endl;

	return 0;
}