text: #ifndef CONTACT_H
  #define CONTACT_H
  #include <string>
  
  using namespace std;
  
  class Contact{
      public:
          Contact(string _num);
          Contact(string _num, string _name);
          Contact(string _num, Contact* _next);
          Contact(string _num, string _name = "NoName", Contact* _next = nullptr);
          string getName()const;
          Contact* getNext()const;
          void setNext(Contact* _next);
          void setName(string _name);
          string getNum()const;
      private:
          string name;
          string num;
          Contact* next;
  };
  
  #endif // CONTACT_H
  