#include <iostream>

#define rep(i,a,b) for(int i=(a);i<(b);i++)
using namespace std;

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

	int *dp;
	dp = new int[1000001]();
	dp[1] = 1;
	dp[2] = 2;
	dp[3] = 2;

	rep(i,4,N+1) dp[i] = (dp[i-2] + dp[i-3])%1000000007;

	cout << dp[N] << " ";

	return 0;
}