#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
#include <limits.h>
#include <time.h>
#include <string>
#include <string.h>
#include <sstream>
#include <set>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <stack>
#include <queue>

using namespace std;

typedef long long ll;

const int KEN = 0;
const int PAR = 1;
const int KENKEN = 2;
const ll MOD = 1000000007;

int main(){
  ll n;
  cin >> n;

  ll dp[n+1][3];
  memset(dp, 0, sizeof(dp));
  dp[1][KEN] = 1;

  for(ll i = 2; i <= n; i++){
    dp[i][KEN] = dp[i-1][PAR] % MOD;
    dp[i][PAR] = (dp[i-1][KEN] + dp[i-1][KENKEN]) % MOD;
    dp[i][KENKEN] = dp[i-1][KEN] % MOD;
  }

  cout << (dp[n][KEN] + dp[n][PAR] + dp[n][KENKEN]) % MOD << endl;

  return 0;
}