#include <bits/stdc++.h>

using namespace std;

typedef unsigned long ulong;

ulong dp[1000001];

int main(int argc, char** argv)
{
	ulong n; cin >> n;

	dp[0] = 1;
	dp[1] = dp[2] = 2;
	for (ulong ii=3; ii<n; ++ii) {
		dp[ii] = (dp[ii-2] + dp[ii-3]) % 1000000007;
	}
	cout << (dp[n-1]) << endl;
	return 0;
}