#include<stdio.h>
#define max(a,b)	(a>b?a:b)
int n;
long long f[100000];
int main()
{
	f[0]=1;
	for(int i=1;i<=3;i++)
	for(int j=i;j<=32768;j++)
	f[j]+=f[j-i];
	scanf("%d",&n);
	printf("%lld",f[n]);
	return 0;
}
/**************************************************************
	Problem: 1885
	User: admin
	Language: C
	Result: Accepted
	Time:17 ms
	Memory:1924 kb
****************************************************************/