#include "bits/stdc++.h"

#define REP(i, n) for(decltype(n) i = 0; i < (n); i++)
#define REP2(i, x, n) for(decltype(x) i = (x); i < (n); i++)
#define RREP(i, n) for (decltype(n) i = (n) - 1;i >= 0; i--)

#define ALL(a) (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define DESCSORT(c) sort(c.begin(), c.end(), greater<int>())

#define LL long long int
#define LD long double

#define INF 999999999
#define PI 3.14159265358979

#define _CRT_SECURE_NO_WARNINGS

using namespace std;

//================================================
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	LL N; cin >> N;
	vector<LL>dp{1, 2, 2};

	REP2(i, 3, N) dp.push_back((dp[i - 3] + dp[i - 2]) % 1000000007);
	cout << dp[N - 1] << "\n";
	return 0;
}