Const keyword for inheritance

I wrote a program like this

#include <iostream> using namespace std;

class Fruit { private:
    string m_name;
    string m_color; public:
    Fruit() = default;
    Fruit(const string& name, const string& color)
        : m_name{name}, m_color{color}
    {
    }
    const string& getName() const{
        return m_name;
    }
    const string& getColor() const{
        return m_color;
    } };

class Apple : public Fruit { private:
    double m_fiber; public:
    Apple() = default;
    Apple(const string& name, const string& color, double fiber)
        : Fruit{name, color}, m_fiber{fiber}
    {
    }
    const double getFiber() const{
        return m_fiber;
    }
    print(){
        cout << "Apple(" << getName() << ", " << getColor() << ", " << getFiber() << ")\n";
    } };

int main() {
    const Apple a{ "Red delicious", "red", 4.2 };
    a.print(); }

This code doesn't compile. However, if I remove the word "const" inside int main() it will work. Why is that?