C/C++ :: Adding Two Phone Agendas Together

I got this problem where I need to create a phone agenda where every name coresponds to a phone number. I decided to create this as a 2 dimensional string array.

But what I do not know how to do is:

I need to create 2 agendas(created in main(ag1 and ag2)) and then add them together to create one big agenda that contains the members of ag1 and ag2.

#include "stdafx.h"
using namespace std;
class Agenda{
string date[20][20];
public:
Agenda();
void afisare();

[Code] ....