#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const int inf = (int)1e9;
const double inf1 = 1e-9;
const int ss = (int)1e6 + 3;
const int base = inf;
bool pred(const pair<int, int>& i, const pair<int, int>& j) {
  if (i.first == j.first)
    return i.second > j.second;
  else
    return i.first > j.first;
}
bool pred2(const int& i, const int& j) { return i > j; }
long long int a[1000005];
int main() {
  long long int n;
  cin >> n;
  a[0] = 1;
  a[1] = 3;
  for (int i = 2; i < 1000005; ++i) {
    a[i] = a[i - 1] + a[i - 2] + 2;
    a[i] %= 1000000007;
  }
  cout << a[n - 1];
  return 0;
}
