Hi.. Here is a program about determining the total number of green-necked vulture eggs counted by all conservationists in the conservation district.

The program in fact works correctly but there is a line which i am not being able to understand its use in the program and it is the line "cin >> next".

Hope to get some explanation about this code..thank you in advance.

```
//DISPLAY 4.9 Nicely Nested Loops
//Determines the total number of green-necked vulture eggs
//counted by all conservationists in the conservation district.
#include <iostream>
using namespace std;
int get_one_total();
//Precondition: User will enter a list of egg counts
//followed by a negative number.
//Postcondition:returns a number equal to the sum of all the egg counts.
int main( )
{
cout << "This program tallies conservationist reports\n"
<< "on the green-necked vulture.\n"
<< "Each conservationist's report consists of\n"
<< "a list of numbers. Each number is the count of\n"
<< "the eggs observed in one"
<< " green-necked vulture nest.\n"
<< "This program then tallies"
<< " the total number of eggs.\n";
int number_of_reports;
cout << "How many conservationist reports are there? ";
cin >> number_of_reports;
int grand_total = 0, subtotal, count;
for (count = 1; count <= number_of_reports; count++)
{
cout << endl << "Enter the report of "
<< "conservationist number " << count << endl;
subtotal = get_one_total ();
cout << "Total egg count for conservationist "
<< " number " << count << " is "
<< subtotal << endl;
grand_total = grand_total + subtotal;
}
cout << endl << "Total egg count for all reports = "
<< grand_total << endl;
return 0;
}
//Uses iostream:
int get_one_total()
{
int total;
cout << "Enter the number of eggs in each nest.\n"
<< "Place a negative integer"
<< " at the end of your list.\n";
total = 0;
int next;
cin >> next;
while (next >= 0)
{
total = total + next;
cin >> next;
}
return total;
}
```