What does this C++ snippet output?

1#include <iostream>
2#include <string>
3#include <memory>
4struct Base {
5  virtual std::string greet() { return "Hello from Base"; }
6};
7struct Derived : Base {
8  std::string greet() override { return "Hello from Derived"; }
9};
10int main() {
11    std::unique_ptr<Base> p = std::make_unique<Derived>();
12    std::cout << p->greet() << "\n";
13}