#include "bits/stdc++.h" using namespace std; #define print(x) cout<<x<<endl; #define rep(i,a,b) for(int i=a;i<b;i++) #define REP(i,a) for(int i=0;i<a;i++) typedef long long ll; typedef pair<int, int> PI; typedef pair<int, PI> V; typedef vector<int> VE; const ll mod = 1000000007; int is_prime(ll n){ for(ll i=3;i*i<=n;i++){ if(n%i==0)return i; } return 0; } int main() { ll n; cin>>n; ll ans=is_prime(n); if(!ans){ if(!n%2){print(n%2);} else print(n); } else { print(ans); } }