#include<bits/stdc++.h>
#define EM 1000000
using namespace std;
using LL = long long;
using P = pair<LL, LL>;
LL LINF = 1e18;
int INF = 1e9;
LL mod = 1e9+7;
using vint = vector<int>;
using vLL = vector<LL>;
using vvint = vector<vector<int>>;
using vvLL = vector<vector<LL>>;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

int main(){
    LL N;
    cin >> N;
//    LL ans = 0;
//    for(LL i = 3;i*i <= N;i++){
//        if(N%i == 0){
//            ans = i;
//            break;
//        }
//    }
//    if(ans == 0){
//        if(N%4 == 0)    ans = 4;
//        else if(N%2 == 0)   ans = N/2;
//        else    ans = N;
//    }
//    cout << ans << endl;
    vector<LL>  l;
    for(LL i = 1;i*i <= N;i++){
        if(N%i == 0)    {
            l.push_back(i);
            l.push_back(N/i);
        }
    }
    sort(l.begin(), l.end());
    for(auto a : l){
        if(a > 2)   {
            cout << a << endl;
            break;
        }
    }
}