#include <bits/stdc++.h>
using namespace std;

int main() {
    int N, K;
    cin >> N >> K;
    stack<int> S;
    int memo[10010];
    for (int i = 1; i <= N; i++) {
        char c;
        cin >> c;
        if (c == '(')
            S.push(i);
        else {
            int t = S.top();
            S.pop();
            memo[i] = t;
            memo[t] = i;
        }
    }
    cout << memo[K] << endl;
}