#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#define sc scanf
#define pr printf
using namespace std;

int n;
int sum;

int main()
{
	sc ("%d",&n);
	sum=n-1;
	
	for (int i=sum; i>sqrt(n); i--)
	{
		if (n%i==0)
		{
			pr ("%d",i);
			break;
		}
	}
	return 0;
}