#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pll> P;

const ll INF = 1ll<<30;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int N;
ll dp[1123456][3];

int main() {
	cin >> N;
	dp[1][0] = dp[2][1] = dp[3][2] = 1;
	FOR(i, 1, N) REP(j, 3) {
		REP(k, 3) if (j != k) {
			if (i + k + 1 <= N) (dp[i + k + 1][k] += dp[i][j]) %= MOD;
		}
	}
	
	ll ans = 0;
	REP(i, 3) ans += dp[N][i];
	ans %= MOD;
	cout << ans << endl;
	return 0;
}