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

int main(){
	int n,k;
	string str;
	cin >> n >> k >> str;
	for(int i = 0; i < n; i++){
		for(int j = i+1; j < n; j++){
			if(str[j] == ' ') continue;
			else if(str[i] == '(' and str[j] == ')'){
				str[i] = ' '; str[j] = ' ';
				//				cout << i+1 << " " << j+1 << endl;
				//				cout << str << endl;
				if(i+1 == k){
					cout << j + 1 << endl;
					return 0;
				}
				if(j + 1 == k){
					cout << i + 1 << endl;
					return 0;
				}
				while(str[i] != '(') i--;
			}
			else break;
		}
	}
	return 0;
}