#include <iostream>
using namespace std;
typedef long long LL;
int main(int argc, char* argv[])
{
	LL N;
	cin>>N;
	LL aw=0;
	while (true){
		int k=1;
		while (N>=k*(k+1)/2){
			k++;
		}
		k--;
		N-=k*(k+1)/2;
		if (N>=0){
			aw++;
		}
		if (N<=0){
			break;
		}
	}
	cout<<aw<<endl;
	return 0;
}