#include<iostream>
using namespace std;
#define FOR(i, a, n) for(int i=a; i<n; i++)
#define RFOR(i, a, n) for(int i=n-1; i>=a; i--)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REMAINDER 1000000007

int dp[1000001];
int main()
{
	int N;
	cin >> N;

	dp[0] = 1;
	dp[1] = dp[2] = 2;
	FOR(i, 3, N) {
		long long sum = dp[i - 2] + dp[i - 3];
		dp[i] = sum % REMAINDER;
	}
	cout << dp[N-1] << endl;

    return 0;
}