#include <iostream>

class Person
{
 public:
  Person(const std::string& f, const std::string& l, int a)
    : firstName(f), lastName(l), age(a)
  {
  }
  std::string firstName;
  std::string lastName;
  int age = -1;
};

int main()
{
  Person melanie("Melanie", "Muster", 42);
  std::cout << melanie.lastName << "," << melanie.firstName
    << ". Alter: " << melanie.age << std::endl;
  return 0;
}