Poj2389

import java.math.BigDecimal;
import java.util.Scanner;


public class Main {

	
	public static void main(String[] args) {
		
		Scanner scan = new Scanner(System.in);
		BigDecimal b1 = scan.nextBigDecimal();
		BigDecimal b2 = scan.nextBigDecimal();
		
		System.out.println(b1.multiply(b2));
	}

}