#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <limits.h>
#include <vector>
#include <numeric>
using namespace std;

int main(){
	int max,target;
	string data;
	vector<int> loc(10000);
	int i;
	
	cin >> max >> target >> data;
	
	//位置保存
	for(int i=0; i<max; i++){
		loc[i] = i + 1;
	}
	
	//解法２どんどん消してく。
	while(true){
		//()を探す
		i = 0;
		while(i+1 < data.length() && (data[i] != '(' || data[i+1] != ')')){
			i ++;
		}
		
		if(data[i] == '(' && data[i+1] == ')'){
			if(loc[i] == target){
				cout << loc[i+1] << endl;
				break;
			}else if(loc[i+1] == target){
				cout << loc[i] << endl;
				break;
			}else{
				data.erase(data.begin() + i, data.begin() + i + 2);
				loc.erase(loc.begin() + i, loc.begin() + i + 2);
			}
		}
	}
	
	return 0;
}