#include <bits/stdc++.h>
using namespace std;
inline long long pow(long long x, long long y, long long mod) {
  long long ans = 1;
  for (; y; y >>= 1, x = (x * x) % mod)
    if (y & 1) ans = (ans * x) % mod;
  return ans % mod;
}
const long long mod = 1000000007;
const int maxn = 100005;
long long fac[maxn << 1];
int main() {
  long long n;
  cin >> n;
  fac[0] = 1;
  for (int i = 1; i <= (n << 1); ++i) fac[i] = fac[i - 1] * i % mod;
  cout << (fac[n << 1] * pow(fac[n] * fac[n] % mod, mod - 2, mod)) % mod - n
       << endl;
  return 0;
}
