//Xinnuo Wang                   CS1A                   chapter 3 , P.147, #18
//
/*******************************************************************************
*
* Caculate the number of slices a pizza
*-------------------------------------------------------------------------------
* This program to calculate the number of slices a pizza of any size 
* can be divided into. 
*
* computation is based on the formula:
* Area = π x r^2
*-------------------------------------------------------------------------------
* INPUT
*    diameter       : The diameter of the pizza in inches
*    radius         : The radius of the pizza in inches
*    area           : The area of the pizza
* OUTPUT
*    numb           : The number of slices a pizza of any size
*
*******************************************************************************/
#include <iostream>
#include <cmath>
using namespace std;

int main() {
	double diameter; //INPUT - The diameter of the pizza in inches
	double radius;   //INPUT - The radius of the pizza in inches
	double area;     //INPUT - The area of the pizza
	double numb;     //OUTPUT - The number of slices a pizza of any size
//
//Input Data
    cout<< "Enter diameter of the pizza in inches" <<endl;
    cin >> diameter;
//
//Compute Radius
    radius = diameter/2;
//
//Compute Area
    area = 3.14156 * pow(radius,2);
//
//Compute the Number of slices
    numb = area/14.125;
//
//Output Result
    cout << "The number of slices is :"<< numb<<endl;
	return 0;
}