#include<iostream>
#include<math.h>
using namespace std;
int main()
{
	int n;
	cin >> n;
	if (n % 2 == 0) { cout << n / 2 << endl; }
	else
	{
		for (int i = 3; i <= n; i += 2)
		{
			int j = 2;
			int k = (int)sqrt((double)i);
			while (j <= k && i % j != 0) { j++; }
			if (j > k)
			{
				if (n % j == 0) { cout << n / j << endl; break; }
			}

		}
	}
	return 0;
}