#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ll long long
using namespace std;

int main(){
	int N;cin >> N;

	int ans=0;
	for(int i=3;i<N;i++){
		ans=max(ans, N/i);
	}
	cout << ans << endl;
}

#include <iostream> 
#include <stdlib.h> 
#include <string.h> 
#include <string> 
#include <sstream>
#include <cstring> 
#include<cmath>
using namespace std;
int main() {
	int x;
	cin >> x;
	cout << x / 3;
	
	return 0;

}