#include <iostream> #include <vector> #include <cstdio> #include <sstream> #include <map> #include <string> #include <algorithm> #include <queue> #include <cmath> #include <set> #include <stack> using namespace std; int main(){ int n, k; cin >> n >> k; k--; string s; cin >> s; int ans = -1; stack<int> x; for(int i=0; i<n; i++){ if(s[i] == '('){ x.push(i); }else{ if(i==k){ ans = x.top(); }else if(x.top() == k){ ans = i; } x.pop(); } } cout << ans+1 << endl; return 0; }