#include<bits/stdc++.h>

using namespace std;
typedef long long ll;
#define sz(s) (int)(s).size()
#define all(s) s.begin(),s.end()

void Speed() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}
const int mod = 1e9 + 7;
vector<pair<int,int>> arr(40);
int n;
const  int N = 30 + 1;
ll dp[N][N][N][N * N];
ll solve(int i , int op , int cl , int sum){
    if(i == n){
        return sum == 0;
    }

    if(sum < 0)
        return 0;
    ll &ret = dp[i][op][cl][sum];
    if(~ret)
        return ret;
    ll ans = 0;

    ans = (ans + solve(i + 1, arr[i + 1].first , arr[i + 1].second , sum)) % mod;
    if(op > 0)
        ans = (ans + op * solve(i , op - 1 , cl , sum + 1) % mod) % mod;
    if(cl > 0)
        ans = (ans + cl * solve(i , op , cl - 1, sum - 1) % mod) % mod;
    return ret = ans;
}

void solve() {
    memset(dp,-1,sizeof dp);
    cin >> n;
    for(int i = 0; i < n; i++){
        string s;
        cin >> s;
        int op = 0 , cl = 0;
        for(auto x : s)
            if(x == '(')
                op++;
            else cl++;
        arr[i] = {op,cl};
    }

    cout << solve(0 , arr[0].first , arr[0].second , 0) << "\n";
}

int main() {
    freopen("count.in", "r", stdin);
    Speed();
    int tc = 1;
    //cin >> tc;
    while (tc--) {
        solve();
    }
    return 0;
}