#include <stdio.h>
#include <string.h>
#include <math.h>

using namespace std;

typedef unsigned long long ull;
int N;

int main(void){
	scanf("%d", &N);

	ull ans[N];

	ans[0] = 1;
	ans[1] = 2;
	ans[2] = 2;

	for(int i = 3;i < N;++i){
		ans[i] = (ans[i-2] + ans[i-3]) % (ull) (1e9 + 7);
	}

	printf("%llu\n", ans[N-1]);
}