#include <bits/stdc++.h>
using namespace std;
int const N = 100001, mod = 1e9 + 7;
int n, m, Open, Close;
string s;
long long dp[3001][3001][2];
long long go(int current, int balance, bool yes) {
  if (balance < 0) return 0;
  if (current == n) return !balance && yes;
  long long &ret = dp[current][balance][yes];
  if (ret + 1) return ret % mod;
  ret = go(current + 1, balance + 1, yes) % mod;
  ret = (ret % mod + go(current + 1, balance - 1, yes) % mod) % mod;
  if (!yes && balance >= Close)
    ret =
        (ret % mod + go(current + 1, balance + (Open - Close), 1) % mod) % mod;
  return ret % mod;
}
int main() {
  scanf("%d%d", &n, &m);
  cin >> s;
  for (int i = 0; i < m; ++i) {
    if (s[i] == '(')
      ++Open;
    else {
      if (Open)
        --Open;
      else
        ++Close;
    }
  }
  n = n - m + 1;
  memset(dp, -1, sizeof dp);
  long long an = go(0, 0, 0) % mod;
  printf("%lld\n", an);
}
