#include <iostream>
#include <vector>
using namespace std;

int main(){
    int N, K;
    cin >> N >> K;
    
    string S;
    cin >> S;
    
    --K;
    
    vector<int> stk;
    for(int i=0;i<S.size();i++){
        if(S[i] == '('){
            stk.push_back(i);
        } else {
            int f = stk.back(); stk.pop_back();
            int b = i;
            
            if(f == K)cout << b + 1 << endl;
            if(b == K)cout << f + 1 << endl;
        }
    }
    
    return 0;
}