#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
bool is_prim(int x){
    if(x == 1)return false;
    for(int i = 2; i <= sqrt(x); i++){
        if(x % i == 0)return false;
    }
    return true;
}
int main(){
    int N;
    while(~scanf("%d",&N)){
        if(N == 0 || N == 1){
            puts("0");continue;
        }
        int i;
        int ans = 0;
        for(i = 1; i <= sqrt(N); i++){
            if(N % i == 0 && is_prim(N/i)){
                ans = i;
                break;
            }
        }
        if(ans){
            printf("%d\n",ans);continue;
        }
            for(int j = sqrt(N); j > 1; j--){
                if(N % j == 0 && is_prim(j)){
                    ans = N / j;
                    break;
                }
        }
        printf("%d\n",ans);
    }
    return 0;
}