//1
import java.util.Scanner;

public class Trapec {

    public static void main(String[] args)       {
        Scanner value = new Scanner(System.in);
          double a = value.nextDouble();
          double b = value.nextDouble();
          double c = value.nextDouble();
          double h = value.nextDouble();
          System.out.println("S: " + ((a+b)*h)/2);

        }
}


//2

import java.util.Scanner;

public class Pravougulnik {

    public static void main (String[] args) {
      Scanner value = new Scanner(System.in);
        double a = value.nextDouble();
        double b = value.nextDouble();
        System.out.println("P = " + (2*a + 2*b));
        System.out.println("S = " + a*b);

    }
}



//3

import java.util.Scanner;

public class Okrujnost {

    public static void main(String[] args)       {
        Scanner value = new Scanner(System.in);
          double r = value.nextDouble();
          System.out.println("C: " + 2*3.14*r );
          System.out.println("S: " + 3.14*(r*r));

        }
}