struct date 
{
  int day;
  int month;
  int year;
};


struct person
{
  char * name;
  int age;
  struct date dob;
};


int string_length(char * my_string);
char * copy_string(char * input);
struct date input_date();
void print_date(char * name, struct date d1);

struct person input_person();
void print_person(char * name, struct person p1);
struct date copy_date(struct date input);
struct person copy_person(struct person p1);
void change_age(struct person * p1);