import java.util.*;
public class A
{
    public static void main(String[] args)
    {
        Scanner sc=new Scanner(System.in);
        float hour=sc.nextFloat();
        float rate=sc.nextFloat();
        if(!sc.hasNextInt)
        {
            System.out.println("Invalid input");
            return;
        }
        if(!(rate>=-10f && rate<=10f))
        {
            System.out.println("Invalid input");
            return;
        }
        if(!(hour>=0f && hour<=24f))
        {
            System.out.println("Invalid input");
            return;
        }
        else
        {
        System.out.printf("%.2f",hour*rate);
        }
    }
}