#include<iostream>
#include<iomanip>
#include<math.h>
#include<algorithm>
#include<string>
#include<vector>
#include<queue>
#include<set>
#include<map>
#include<tuple>
#include<complex>
#define REP(i, N) for(ll i = 0; i < N; ++i)
#define FOR(i, a, b) for(ll i = a; i < b; ++i)
#define ALL(a) (a).begin(),(a).end()
#define pb push_back
#define INF (long long)1000000000
#define MOD 1000000007
#define EPS (long double) 1e-8
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> P;
int dh[4] = {1, 0, -1, 0};
int dw[4] = {0, 1, 0, -1};

using namespace std;

int main() {
	int n;
	cin>>n;
	vector<vector<ll> > dp(3, vector<ll>(n + 1, 0));
	dp[0][0] = 1;
	dp[1][0] = 1;
	dp[2][0] = 1;
	FOR(i, 1, n + 1) {
		if(i == 1) dp[0][i] = 1;
		else dp[0][i] = (dp[1][i - 1] + dp[2][i - 1]) % MOD;;
		if(i > 1) {
			if(i == 2) dp[1][i] = 1;
			else dp[1][i] = (dp[0][i - 2] + dp[2][i - 2]) % MOD;
		}
		if(i > 2) {
			if(i == 3) dp[2][i] = 1;
			else dp[2][i] = (dp[0][i - 3] + dp[1][i - 3]) % MOD;
		}
	}
	ll res = dp[0][n] + dp[1][n] + dp[2][n];
	res = res % MOD;
	cout<<res<<endl;
}