#include <bits/stdc++.h> using namespace std; typedef long long ll; typedef vector<int> VI; typedef vector<VI> VVI; typedef vector<ll> VL; typedef vector<VL> VVL; typedef pair<int, int> PII; #define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i) #define REP(i, n) FOR(i, 0, n) #define ALL(x) x.begin(), x.end() #define MOD 1000000007 #define INF (1LL<<25) //33554432 #define PI 3.14159265359 #define EPS 1e-12 //#define int ll signed main(void) { ll n; cin >> n; VL v; for(ll i=1; i*i<=n; ++i) { //cout << i << " " << n%i << endl; if(n%i == 0) { //cout << "a" << endl; v.push_back(i); if(i*i != n) v.push_back(n/i); } } sort(ALL(v)); for(ll i: v) { //cout << i << endl; if(i >= 3) { cout << i << endl; break; } } return 0; }