#include <bits/stdc++.h>
#define rep(i,n) for(ll i=0, i##_len=(n); i<i##_len; ++i)
#define REP(i,num,n) for(ll i=num, i##_len=(n); i<i##_len; ++i)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((ll)(x).size())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
#define MEMSET(v, h) memset((v), h, sizeof(v))
#define pb push_back
#define mp make_pair
#define y0 y3487465
#define y1 y8687969
#define j0 j1347829
#define j1 j234892
typedef long long ll;
ll INF = 1e18;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
using namespace std;

ll dp[1000001][4];
int main(){
  ll MOD = 1000000007;
  ll N; cin >> N;
  dp[1][1] = 1;
  dp[2][2] = 1;
  dp[3][3] = 1;
  
  REP(i,1,N){
    dp[i+1][1] = (dp[i+1][1]+dp[i][2]+dp[i][3]) % MOD;
    dp[i+2][2] = (dp[i+2][2]+dp[i][1]+dp[i][3]) % MOD;
    dp[i+3][3] = (dp[i+3][3]+dp[i][2]+dp[i][1]) % MOD;
  }
  
  ll ans = 0;
  REP(i,1,4){
    ans = (ans + dp[N][i]) % MOD;
  }
  
  cout << ans << endl;



  return 0;
}