#include <bits/stdc++.h>
using namespace std;
const int maxn = 2005;
const int mod = 1e9 + 7;
long long dp[maxn][maxn];
int n, m;
char s[100005];
int main() {
  dp[0][0] = 1;
  for (int i = 1; i <= 2000; i++) {
    dp[i][0] = dp[i - 1][1];
    for (int j = 1; j <= i; j++) {
      dp[i][j] = (dp[i - 1][j - 1] + dp[i - 1][j + 1]) % mod;
    }
  }
  scanf("%d%d", &n, &m);
  scanf("%s", s + 1);
  int sum = 0, l = 0, r = 0;
  for (int i = 1; i <= m; i++) {
    if (s[i] == '(')
      sum++;
    else
      sum--;
    l = min(sum, l);
  }
  l = -l;
  sum = 0;
  for (int i = m; i; i--) {
    if (s[i] == ')')
      sum++;
    else
      sum--;
    r = min(sum, r);
  }
  r = -r;
  long long ans = 0;
  for (int i = 0; i <= n - m; i++) {
    for (int j = 0; j <= n - m; j++) {
      int len2 = n - m - i;
      int j2 = j - sum;
      if (j2 <= n - m && i >= l && j2 >= r) {
        ans = (ans + dp[i][j] * dp[len2][j2]) % mod;
      }
    }
  }
  cout << ans << endl;
}
