#include <iostream>
using namespace std;

long long mod = 1000000007;
long long ken, kenken, pa, next_ken, next_kenken, next_pa;

int main() {
	cin.tie(0); ios::sync_with_stdio(false);
	int N; cin >> N;
	ken = 1; kenken = 0; pa = 0;
	for (int i = 2; i <= N; i++) {
		next_ken = pa; next_kenken = ken; next_pa = (ken + kenken);

		ken = next_ken; kenken = next_kenken;
		pa = (next_pa > mod) ? next_pa%mod : next_pa;
	}
	cout << (ken + kenken + pa) % mod << endl;
	return 0;
}