0. enum class KindType: cat, dog,...
1. стурктура Animal
  - kind
  - name
2. структура Person:
 - surname
 - name
 - список домашних животных pets

#include <string>

enum class KindType {
    cat,
    dog,
    bear,
    elephant,
};

struct Animal {
    KindType kind;
    std::string name;
};

struct Person {
    std::string surname;
    std::string name;
    std::vector<Animal> pets;
};

void read(Animal& a) {
    std::string kind;
    std::cin >> kind >> a.name;
    if (kind == "cat") {
        a.kind = KindType::cat;
    } else if (kind == "dog") {
        a.kind = KindType::dog;
    } else if (kind == "bear") {
        a.kind = KindType::bear;
    } else if (kind == "elephant") {
        a.kind = KindType::elephant;
    }
}

bool operator < (const Person& p1, const Person& p2) {
    if (p1.surname != p2.surname) {
        return p1.surname < p2.surname;
    }
    return p1.name < p2.name;
co}

/*bool operator < (const Person& p1, const Person& p2) {
    return std::tie(p1.surname, p1.name) < std::tie(p2.surname, p2.name);
}*/

bool compare_by_pets(const Person& a, const Person& b) {
    return a.pets.size() > b.pets.size();
}

bool compare_by_pets2(const Person& a, const Person& b) {
    return a.pets.size() > b.pets.size();
}

int main() {
    Animal z;
    read(z);

    std::vector<Person> persons;
    sort(persons.begin(), persons.end());

    expression ? (if true) : (if false)

    int v = false ? 123 : 567;
    sort(persons.begin(), persons.end(), flag ? compare_by_pets : compare_by_pets2);
    if (flag)
        sort(persons.begin(), persons.end(), compare_by_pets);
    else
        sort(persons.begin(), persons.end(), compare_by_pets2);


    // 1. surname, name
    //

}