Person / Pupil classes

#include <iostream>
#include <string>

using namespace std;

class Person{
  public:
    string name, birthDate;

    Person(string name, string date){
      this->name = name;
      this->birthDate = date;
    }

    void print(){
      cout << "Person: {Name: " << name << ", Birth Date: " << birthDate << "}";
    }
};

class Teacher : public Person{
  public:
    string category, classes[36];

    Teacher(string name, string date, string category, string classes[], int classesLength) : Person(name, date){
      this->category = category;
      if(classesLength <= 36) for(int i = 0; i < classesLength; i ++) this->classes[i] = classes[i];
    }

    void print(){
      cout << "Teacher: {Name: " << name << ", Birth Date: " << birthDate << ", Category: " << category << ", Classes: ";
      for(int i = 0; i < 36; i++){
        if(classes[i] == "") break;
        else cout << classes[i] << " ";
      }
      cout << "}";
    }

    void next(){
      string newClasses[36];
      int index = 0;
      for(int i = 0; i < 36; i ++){
        if(classes[i] != ""){
          string element = classes[i];
          int c = stoi(element.substr(0, element.length() - 1)) + 1;
          if(c <= 11){
            newClasses[index] = to_string(c) + element.substr(element.length() - 1, 1);
            index++;
          }
          else classes[i] = "";
        }
      }
      for(int i = 0; i < 36; i++) classes[i] = newClasses[i];
    }
};

class Pupil : public Person{
  public:
    string project, m_class;

    Pupil(string name, string date, string project, string theClass) : Person(name, date){
      this->project = project;
      this->m_class = theClass;
    }

    void print(){
      cout << "Pupil: {Name: " << name << ", Birth Date: " << birthDate << ", Class: " << m_class << ", Project: " << project << "}";
    }
};

void info(Person *people[], int amount){
  cout << "Info: {\n";
  for(int i = 0; i < amount; i++) {
    people[i]->print();
    cout << "\n";
  }
  cout << "}";
}

int main(){
  string classes[5] = {"10A", "11B", "5C"};
  Teacher *teacher = new Teacher("Teacher's Name", "10.10.2010", "Biology", classes, 5);
  cout << "Teacher before next():" << endl;
  teacher->print();
  cout << endl << "Teacher after next():" << endl;
  teacher->next();
  teacher->print();

  cout << endl << endl;
  Person* people[] = {new Pupil("Pupil's Name 1", "11.10.2021", "Pupil's project", "10B"), new Pupil("Pupil's Name 2", "11.10.2021", "Pupil's project", "10B"), teacher};
  info(people, 3);
}