#include <bits/stdc++.h>
using namespace std;
const int N = 2e5;
int read() {
  int x = 0, w = 1;
  char ch = 0;
  while (ch < '0' || ch > '9') {
    if (ch == '-') w = -1;
    ch = getchar();
  }
  while (ch <= '9' && ch >= '0') {
    x = (x << 1) + (x << 3) + ch - '0';
    ch = getchar();
  }
  return x * w;
}
int n, k, m, tot, now;
char s[N], ans[N];
int main() {
  n = read();
  k = read();
  m = n - k;
  if (!n) {
    putchar('\n');
    return 0;
  }
  scanf("%s", s + 1);
  for (int i = 1; i <= n; ++i) {
    if (s[i] == '(') ans[++tot] = '(';
    if (s[i] == ')') {
      if (m > 0) {
        m -= 2;
        --tot;
      } else
        ans[++tot] = ')';
    }
  }
  for (int i = 1; i <= tot; ++i) putchar(ans[i]);
  putchar('\n');
  return 0;
}
