// program to print the product of all the multiples of 5 from 5
// to the entered number.
#include <iostream>
using namespace std;

int main()
{
   int number;
   int counter;
   int product;
   
   cout << "Enter a positive number -- ";
   cin >> number;

   // using a while loop
   product = 1;
   counter = 5;
   while (counter <= number) {
      product = product * counter;
      counter = counter + 5;
   }
   cout << "The product of all multiples of 5 from 5 to " << number
	<< " is " << product << endl;
   
   // using a do-while loop
   product = 1;
   counter = 5;
   do {
      if (counter <= number) {
	 product = product * counter;
	 counter = counter + 5;
      }
   } while (counter <= number);
   cout << "The product of all multiples of 5 from 5 to " << number
	<< " is " << product << endl;

   // using a for loop
   product = 1;
   for(counter = 5; counter <= number; counter+=5)
      product = product * counter;
   cout << "The product of all multiples of 5 from 5 to " << number
	<< " is " << product << endl;

   return 0;
}