import java.util.*;
class Main{
    public static void main(String args[])
    {
        Scanner s=new Scanner(System.in);
        if(!s.hasNextInt())
        {
            System.out.println("Invalid input");
            return;
        }
        int h=s.nextInt();
        if(!s.hasNextFloat)
        {
             System.out.println("Invalid input");
            return; 
        }
        float r=s.nextFloat();
        float t=h*r;
        System.out.printf("%.2f",t);
    }
}