#include<bits/stdc++.h>
using namespace std;  
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
#define rep(i,n) for(ll i=0;i<(n);i++)  
#define pii pair<int,int>
#define piii pair<int,pii>
#define mp make_pair
#define pb push_back  
#define ALL(a) (a).begin(),(a).end()
#define FST first
#define SEC second  
const int INF = (INT_MAX/2);
const ll LINF = (LLONG_MAX/2);
const double eps = 1e-14;
const double PI = M_PI;  
#define DEB cout<<"!"<<endl
#define SHOW(a,b) cout<<(a)<<" "<<(b)<<endl
#define SHOWARRAY(ar,i,j) REP(a,i)REP(b,j)cout<<ar[a][b]<<((b==j-1)?((a==i-1)?("\n\n"):("\n")):(" "))
  
#define DIV 1000000007

typedef vector<ll> Array;
typedef vector<Array> matrix;

int dp1[1000003];
int dp2[1000003];
int dp3[1000003];

int main(){
  ll n; cin >> n;
  
  fill_n(dp1,1000003,0);
  fill_n(dp2,1000003,0);
  fill_n(dp3,1000003,0);
  
  dp1[1] = 1;
  dp2[2] = 1;
  dp3[3] = 1;
  
  for(int i=0;i <= n; i++){
    dp1[i+1] += dp2[i]%DIV + dp3[i] % DIV;
    dp2[i+2] += dp1[i]%DIV + dp3[i]%DIV;
    dp3[i+3] += dp1[i]%DIV + dp2[i] %DIV;
    dp1[i+1] %= DIV;
    dp2[i+2] %= DIV;
    dp3[i+3] %= DIV;
    
  }
  cout << (((dp1[n]+dp2[n])%DIV)+dp3[n])%DIV << endl;
  
  return 0;
}