E0265 член "street::ulitsa" (объявлено строка 11) недоступен

#include <iostream>
#include <string>



using namespace std;

class street{
private:

    string ulitsa;
public:
    street(string ulitsa) {
        this->ulitsa = ulitsa;
    }
    friend void print_info(street& stre, tree& dere);

};

class tree{
private:
    string name;
    float tall;
public:
    tree(string name, float tall) {
        this->name = name;
        this->tall = tall;
    }
    friend void print_info(street& stre, tree& dere);
};

void print_info(street& stre, tree& dere) {
    cout << "на " << stre.ulitsa << "растет " << dere.name << dere.tall << "высоты";
}


int main() {
    setlocale(LC_ALL, "RU");

    street hz("пешков стрит 4");
    tree der("сиквоя", 3.4);
    
        
        

    return 0;
}