#include <iostream>
#include <cstdarg>
using namespace std;

//First argument will represent the number of
//arguments
double average(int num,...)
{
   va_list valist;
   double sum = 0.0;
   int i1 ;
   va_start(valist, num); //initialize valist for num number of arguments
   for (i1 = 0; i1 < num; i1++)
   { //access all the arguments assigned to valist
      sum += va_arg(valist, int);
   }
   va_end(valist); //clean memory reserved for valist
   return sum/num;
}

int main()
{
   cout << "Average of 2, 3, 4, 5 = "<< average(4, 2,3,4,5) << endl;
   cout << "Average of 5, 10, 15 = "<< average(3, 5,10,15)<< endl;
}