using System;

public class Program

{

    static double rectangle(double a, double b)

    {

        return a * b;

    }

    public static void Main()

    {

        Console.Write("a = ");

        double a = double.Parse(Console.ReadLine());;

        Console.Write("b = ");

        double b = double.Parse(Console.ReadLine());;

        Console.Write("a1 = ");

        double a1 = double.Parse(Console.ReadLine());;

        Console.Write("b1 = ");

        double b1 = double.Parse(Console.ReadLine());;

        Console.Write("a2 = ");

        double a2 = double.Parse(Console.ReadLine());;

        Console.Write("b2 = ");

        double b2 = double.Parse(Console.ReadLine());;

        Console.Write("a3 = ");

        double a3 = double.Parse(Console.ReadLine());;

        Console.Write("b3 = ");

        double b3 = double.Parse(Console.ReadLine());;

        Console.Write("a4 = ");

        double a4 = double.Parse(Console.ReadLine());;

        Console.Write("b4 = ");

        double b4 = double.Parse(Console.ReadLine());;

        Console.WriteLine(rectangle(a, b));

        Console.WriteLine(rectangle(a1, b1));

        Console.WriteLine(rectangle(a2, b2));

        Console.WriteLine(rectangle(a3, b3));

        Console.WriteLine(rectangle(a4, b4));

    }

}