//DB entry
#include <cstdio>
struct List
{
    char *name;
    unsigned int phone_number;
    List *next;
};
List *Find(List *ls, const char *name_to_find);
void Add(List *&ls, const char *new_name, unsigned int new_phone);
void Del_elem(List *&ls, const char * name_to_delete);
void PrintToFile (List * ls, FILE * fl);