#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef vector vi; typedef vector vvi; #define rep(i,n) for(ll i=0;i<(n);i++) #define tii tuple #define tiii tuple #define mt make_tuple #define pb push_back #define ALL(a) (a).begin(),(a).end() #define FST first #define SEC second const int INF = (INT_MAX/2); const ll LLINF = (LLONG_MAX/2); const double eps = 1e-5; const double PI = M_PI; #define DEB cerr<<"!"<0){if((n&1)==1)r=r*x%m;x=x*x%m;n>>=1;}return r%m;} int main(){ ll n; cin >> n; for(ll i = 3; i*i <= n;i++) if(n%i == 0){ cout << i << endl; return 0; } if(n==4) cout << 4 << endl; else if(n%2 == 0) cout << n/2 << endl; else cout << n << endl; return 0; }