#include <bits/stdc++.h>
using namespace std;
const int maxn = 3010;
const int mod = 1e9 + 7;
long long dp[maxn][maxn];
void get_() {
  dp[0][0] = 1;
  for (int i = 1; i <= 2010; i++) {
    for (int j = 0; j <= i; j++) {
      if (j) dp[i][j] = (dp[i][j] + dp[i - 1][j - 1]) % mod;
      dp[i][j] = (dp[i][j] + dp[i - 1][j + 1]) % mod;
    }
  }
}
int main() {
  get_();
  int n, m;
  while (scanf("%d %d", &n, &m) != EOF) {
    int pre = 0;
    int mi = 0;
    for (int i = 1; i <= m; i++) {
      char tmp;
      scanf(" %c", &tmp);
      if (tmp == '(')
        pre++;
      else
        pre--;
      mi = min(pre, mi);
    }
    long long sum = 0;
    for (int i = 0; i <= n - m; i++) {
      for (int j = 0; j <= i; j++) {
        if (mi + j >= 0 && j + pre <= n - m - i) {
          (sum += ((dp[i][j] % mod * dp[n - m - i][pre + j] % mod) % mod)) %=
              mod;
        }
      }
    }
    printf("%lld\n", sum % mod);
  }
  return 0;
}
