#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;
#define MOD 1000000007

int dp[3][1000005];

int main(){
  int N;
  cin >> N;
  
  rep(i,N){
    if(i==0){
      dp[0][1] = 1;
      dp[1][2] = 1;
      dp[2][3] = 1;
    }else{
      dp[0][i+1] += dp[1][i] + dp[2][i];
      dp[0][i+1] %= MOD;
      dp[1][i+2] += dp[0][i] + dp[2][i];
      dp[1][i+2] %= MOD;
      dp[2][i+3] += dp[0][i] + dp[1][i];
      dp[2][i+3] %= MOD;
    }
  }
  cout << (dp[0][N] + dp[1][N] + dp[2][N])%MOD << endl;
  
  return 0;
}