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

public class Main {

    public static void main(String[] args) {
	// write your code here


        Scanner scan = new Scanner(System.in);
        BigDecimal N= scan.nextBigDecimal();
        BigDecimal M= scan.nextBigDecimal();
        BigDecimal b3 = N.multiply(M);
BigDecimal p = b3.setScale(0, BigDecimal.ROUND_DOWN);;
        System.out.println(p);
 


    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz