#include<bits/stdc++.h>
using namespace std;

int main(){
    long long N; cin >> N;
    map<long long,int> table;
    for(long long i=2;i*i<=N;i++){
        while(N%i==0){
            N/=i;
            table[i]++;
        }
        table[N]++;
    }
    for(auto s:table){
        if(s.first==2||s.first==1) continue;
        else{
            cout << s.first << endl;
            return 0;
        } 
    }
}