#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int n;
void gcd(int a, int b, int &d, int &x, int &y) {
  if (!b) {
    d = a;
    x = 1;
    y = 0;
  } else {
    gcd(b, a % b, d, y, x);
    y -= x * (a / b);
  }
}
int inv(int a) {
  int d, x, y;
  gcd(a, mod, d, x, y);
  return x;
}
int solve(int _n, int x) {
  long long ret = 1;
  while (_n--) {
    ret *= x;
    ret %= mod;
    x--;
  }
  return ret;
}
int main() {
  while (scanf("%d", &n) == 1 && n) {
    int ans = (long long)solve(n, 2 * n - 1) * inv(solve(n, n)) % mod;
    ans = ans * 2 - n;
    ans = (ans % mod + mod) % mod;
    printf("%d\n", ans);
  }
  return 0;
}
