#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<climits>
#include<cstdlib>
#include<ctime>
#include<cctype>
#include<algorithm>
#include<set>
#include<map>
#include<vector>
#include<stack>
#include<queue>
#include<deque>
#include<string>
#include<sstream>
#include<iomanip>
using namespace std;
//=====================struct declaration======================

//=====================var declarartion========================
int n;
//=====================function declaration====================

//=====================main code===============================
int main()
{
	freopen("prime.in","r",stdin);
	freopen("prime.out","w",stdout);
	
	cin>>n;
	
	for(int i=2; i<n; i++)
	{
		if(n%i==0)
		{
			int x=2;
			while(x<=sqrt(i) && i%x!=0)
				x++;
			if(x>sqrt(i) && i>0)
			{
				int y=2;
				while(y<=sqrt(n/i) && (n/i)%y!=0)
					y++;
				if(y>sqrt(n/i) && n/i>0)
				{
					if((n/i)>i)
						cout<<n/i<<endl;
					else
						cout<<i<<endl;
					break;
				}
			}
		}
	}
	
	return 0;
}