#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ul;
typedef signed long long ll;
ul over = 1000000007;

int main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed;
  ll n;
  cin >> n;
  ll dp[n][3];
  dp[0][0] = 0; dp[0][1] = 1; dp[0][2] = 0;
  for (ll i = 1; i < n; ++i) {
    dp[i][0] = dp[i-1][1] + dp[i-1][2];
    dp[i][1] = dp[i-1][0];
    dp[i][2] = dp[i-1][1];
    dp[i][0] %= 1000000007;
    dp[i][1] %= 1000000007;
    dp[i][2] %= 1000000007;
  }
  cout << (dp[n-1][0] + dp[n-1][1] + dp[n-1][2])%1000000007 << endl;
  return 0;
}