// #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include <bits/stdc++.h> #include <atcoder/all> using namespace std; using namespace atcoder; using mint = modint998244353; // using mint = modint1000000007; using ll = long long; using ull = unsigned long long; using ld = long double; using pii = pair<int, int>; using pll = pair<ll, ll>; using T = tuple<int, int, int>; using G = vector<vector<int>>; #define rep(i, n) for (ll i = 0; i < (n); ++i) #define rep2(i, a, b) for (ll i = a; i < (b); ++i) #define rrep2(i, a, b) for (ll i = a-1; i >= (b); --i) #define rep3(i, a, b, c) for (ll i = a; i < (b); i+=c) #define rng(a) a.begin(),a.end() #define rrng(a) a.rbegin(),a.rend() #define popcount __builtin_popcount #define popcountll __builtin_popcountll #define fi first #define se second #define UNIQUE(v) sort(rng(v)), v.erase(unique(rng(v)), v.end()) #define MIN(v) *min_element(rng(v)) #define MAX(v) *max_element(rng(v)) #define SUM(v) accumulate(rng(v),0) template<class T> bool chmin(T &a,T b){if(a>b){a=b;return 1;}else return 0;} template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;} template<class T> void printv(vector<T> &v){rep(i,v.size())cout<<v[i]<<" \n"[i==v.size()-1];} template<class T> void printvv(vector<vector<T>> &v){rep(i,v.size())rep(j,v[i].size())cout<<v[i][j]<<" \n"[j==v[i].size()-1];cout<<endl;} const ll dx[] = {0, 1, 0, -1}; const ll dy[] = {1, 0, -1, 0}; const ll dxx[] = {0, 1, 0, -1, 1, -1, 1, -1}; const ll dyy[] = {1, 0, -1, 0, 1, 1, -1, -1}; const ll LINF = 1001002003004005006ll; const int INF = 1001001001; int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); int n, k; cin >> n >> k; k--; string s; cin >> s; vector<int> stk, ans(n); rep(i, n){ if (s[i] == '(') stk.push_back(i); else{ int j = stk.back(); stk.pop_back(); ans[i] = j; ans[j] = i; } } cout << ans[k] + 1 << endl; return 0; }