// yukicoder: No.314 ケンケンパ
// 2019.4.14 bal4u

#include <stdio.h>

#define MOD 1000000007

int f[1000006] = { 0, 1, 2, 2, 3, 4, 5, 7, 9, 12, 16 };

int calc(int n)
{
	int i;
	if (n <= 10) return f[n];
	for (i = 11; i <= n; i++) {
		f[i] = f[i - 3] + f[i - 2];
		if (f[i] >= MOD) f[i] -= MOD;
	}
	return f[n];
}

int main()
{
	int N;
	scanf("%d", &N);
	printf("%d\n", calc(N));
	return 0;
}