#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n;
  cin >> n;
  long long int dp1[n + 1], dp2[n + 1];
  memset(dp1, 0, sizeof(dp1));
  memset(dp2, 0, sizeof(dp2));
  dp1[1] = 1;
  dp1[2] = 2;
  dp2[1] = 1;
  dp2[2] = 2;
  if (n == 1) {
    cout << dp1[1];
    return 0;
  }
  if (n == 2) {
    cout << 3;
    return 0;
  }
  long long int md = 1000000007;
  long long int ans = 0;
  ans = 3;
  for (long long int i = 3; i <= n; i++) {
    dp1[i] = dp2[i - 1] + 1;
    dp2[i] = dp2[i - 2] + dp1[i];
    dp1[i] %= md;
    dp2[i] %= md;
    ans += dp1[i];
    ans %= md;
  }
  cout << ans << endl;
  return 0;
}
