class Student { private: int age; int standard; string first_name; string last_name;

public: // Setters void set_age(int a) { age = a; }

void set_standard(int s) {
    standard = s;
}

void set_first_name(string fn) {
    first_name = fn;
}

void set_last_name(string ln) {
    last_name = ln;
}

// Getters
int get_age() {
    return age;
}

string get_last_name() {
    return last_name;
}

string get_first_name() {
    return first_name;
}

int get_standard() {
    return standard;
}

// Correct to_string() function
string to_string() {
    stringstream ss;
    ss << age << "," << first_name << "," << last_name << "," << standard;
    return ss.str();
}

};