#include <iostream>
#include <string>
#include <set>
#include <map>
#include <vector>
#include <numeric>
#include <tuple>
#include <cstdio>
#include <assert.h>

using namespace std;

typedef long long ll;


#define rep(i,b) for(ll i=0;i<(b);++i)
#define rep1(i,b) for(ll i=1;i<=(b);++i)
#define vec vector
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl;

int N;
#define MOD 1000000007
ll dp[1000010][3];

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