#include <bits/stdc++.h>
using namespace std;
long long n;
long long ans[100100 << 1];
long long ksm(long long p, long long q) {
  long long res = 1;
  while (q) {
    if (q & 1) res = res * p % 1000000007;
    p = p * p % 1000000007;
    q >>= 1;
  }
  return res;
}
signed main() {
  cin >> n;
  ans[0] = 1;
  for (long long i = 1; i <= (n << 1); i++) {
    ans[i] = ans[i - 1] * i % 1000000007;
  }
  cout << (ans[n << 1] * ksm(ans[n] * ans[n] % 1000000007, 1000000007 - 2)) %
                  1000000007 -
              n;
  return 0;
}
