#include <iostream>
using namespace std;
int main() {
	long long n;
	cin >> n;
	long long a = 1, b = 1, e = 0, c = 1;
	for (int i = 3; i <= n; ++i) {
		e = a + b;
		a = b;
		b = e;
		if (i == n)
			c = e;
	}
	cout << c % 1000000007;
}