import java.math.BigDecimal;
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    }
} import java.math.BigDecimal; BigDecimal java.math import java.util.*; util.* java public class Main{
    public static void main(String[] args){
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    }
} Main public static void main(String[] args){
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    } main {
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    } Scanner scan = new java.util.Scanner(System.in); scan new java.util.Scanner(System.in) BigDecimal a = new BigDecimal(Long.toString(scan.nextLong())); a new BigDecimal(Long.toString(scan.nextLong())) BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble())); b new BigDecimal(Double.toString(scan.nextDouble())) System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN)) System.out.println System.out System System.out a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN) a.multiply(b).setScale a.multiply(b) a.multiply a b 0 BigDecimal.ROUND_DOWN BigDecimal BigDecimal.ROUND_DOWN scan.close() scan.close scan String[] args args public class Main{
    public static void main(String[] args){
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    }
} public class Main{
    public static void main(String[] args){
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    }
} Main
import java.math.BigDecimal;
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner scan = new java.util.Scanner(System.in);
        BigDecimal a = new BigDecimal(Long.toString(scan.nextLong()));
        BigDecimal b = new BigDecimal(Double.toString(scan.nextDouble()));
        System.out.println(a.multiply(b).setScale(0, BigDecimal.ROUND_DOWN));
        scan.close();
    }
}