#include <bits/stdc++.h>
#pragma GCC optimize(O3)
using namespace std;
long long c = 0, d, e, a, b, res = 1e18, mas[200001], mas2[200000], f, z, res2,
          mas3[1000], array57[10][100000], mas4[100], r1, r2;
long long base = 57, p = 1e9 + 7, ans = 10000, sum, sum2, uk1, uk2, heh, heh2;
char ch;
string s, s2, s3, s4;
set<pair<long long, long long>> mset;
vector<pair<long long, long long>> vec;
deque<long long> ord, answer[5000], vec2;
map<pair<long long, long long>, long long> map57;
multiset<long long> mset57;
long long map1[5000], map2[5000][101];
long long get_sum(vector<long long> a) {
  long long answer2 = 0, r = 1;
  for (int i = 0; i < a.size(); i++) {
    answer2 += r * a[i];
    r *= 2;
  }
  return answer2;
}
signed main() {
  srand(time(0));
  cin >> a >> b;
  cin >> s;
  for (int i = 0; i < a; i++) {
    if (s[i] == '(') {
      mas[c] = d;
      mas2[i] = d;
      c++;
      d++;
    } else {
      c--;
      mas2[i] = mas[c];
    }
  }
  e = a - b;
  e /= 2;
  for (int i = 0; i < a; i++) {
    if (mas2[i] >= e) {
      cout << s[i];
    }
  }
  cin >> a;
  return 0;
}
