TGBRACKETS

#define task "TGBRACKETS"
#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

using ll = long long;
using ld = long double;

constexpr int N = 5e2 + 5;
constexpr int mod = 1e9 + 7;
int n;
string s;
int dp[N][N][N / 2];

void Read()
{
    cin >> n >> s;
    s = " " + s;
}

#define Match(x, y) (x != y)

int f(int x, int y, int sum)
{
    int &ans = dp[x][y][sum];
    if (ans != -1)
        return ans;

    ans = 0;

    if (x >= y)
        return ans = 1;

    ans = ((f(x + 1, y, sum) + f(x, y - 1, sum)) % mod - f(x + 1, y - 1, sum)) % mod;

    if (Match(s[x], s[y]) && (s[x] == '(' || sum > 0))
        (ans += f(x + 1, y - 1, sum + (s[x] == '(' ? 1 : -1))) %= mod;

    return ans;
}

void Solve()
{
    memset(dp, -1, sizeof dp);

    cout << (f(1, n, 0) - 1 + mod) % mod;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }

    Read();
    Solve();
}