#include "bits/stdc++.h"
using namespace std;

typedef long long ll;
ll pr = (ll)(1e9+7);

int main() {
	int N;
	cin >> N;

	vector<ll> dp(N+1);
	dp[0]=0; dp[1]=1; dp[2]=2, dp[3]=2;

	for (int i = 3; i < N; i++) {
		dp[i+1] = dp[i-1] + dp[i-2];
		dp[i+1] %= pr;
	}

	cout << dp[N] << endl;

}