#include using namespace std; int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); long long n; cin >> n; for(long long i = 3; i <= (long long)sqrt(n); i++){ if(n % i == 0){ cout << i << endl; return 0; } } if(n % 2 == 0 and n > 4){ cout << n / 2 << endl; }else{ cout << n << endl; } return 0; }