1 #include <iostream>
2 using namespace std;
3
4 const int mod = 1e9+7;
5
6 long long qmi(long long a, long long k, long long p)
7 {
8 long long res = 1;
9 while (k)
10 {
11 if (k & 1) res = res * a % p;
12 a = a * a % p;
13 k >>= 1;
14 }
15 return res;
16 }
17
18 int main(){
19 long long n;cin >> n;
20 long long res = 1;
21 for(int i = 2*n;i > n;--i) res = res * i % mod;
22 for(int i = 1;i <= n;++i) res = res * qmi(i, mod-2, mod) % mod;
23 res = res * qmi(n+1, mod-2, mod) % mod;
24 cout << res << endl;
25 return 0;
26 }
