first_ex_1.cpp

#include <math.h>
#include <iostream>
#include <stdlib.h>

using namespace std;
int main ()
{
   cout << "ABBCCCDDDD" << endl; 
   
   cout << "A" << endl; 
   cout << "BB" << endl; 
   cout << "CCC" << endl; 
   cout << "DDDD" << endl; 
   system("pause");
}