#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
bool judge (int x) {
    for (int i = 2;i < (int) sqrt(x);i++) {
        if (x % i == 0) {
            return false;
        }
    }
    return true;
}
int main () {
    int n;
    cin >> n;
    for (int i = 2;i < n;i++) {
        int j = n / i;
        if (i * j == n) {
            if (judge(i) && judge(j)) {
                cout << j << endl;
                return 0;
            }
        }
    }
    return 0;
}