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

public class Main {
    public static void main(String[] args) throws FileNotFoundException {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    }
} import java.io.FileNotFoundException; FileNotFoundException java.io import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) throws FileNotFoundException {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    }
} Main public static void main(String[] args) throws FileNotFoundException {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    } main {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double A = sc.nextDouble(); A sc.nextDouble() sc.nextDouble sc BigDecimal B = BigDecimal.valueOf(sc.nextDouble()); B BigDecimal.valueOf(sc.nextDouble()) BigDecimal.valueOf BigDecimal sc.nextDouble() sc.nextDouble sc BigDecimal times = B.multiply(BigDecimal.valueOf(A)); times B.multiply(BigDecimal.valueOf(A)) B.multiply B BigDecimal.valueOf(A) BigDecimal.valueOf BigDecimal A System.out.println(times.longValue()) System.out.println System.out System System.out times.longValue() times.longValue times String[] args args public class Main {
    public static void main(String[] args) throws FileNotFoundException {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    }
} public class Main {
    public static void main(String[] args) throws FileNotFoundException {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    }
} Main
import java.io.FileNotFoundException;
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws FileNotFoundException {

//    	File file = new File("src/in.txt");

        //コード
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);

    	double A = sc.nextDouble();
    	BigDecimal B = BigDecimal.valueOf(sc.nextDouble());
    	//double B = sc.nextDouble();

    	BigDecimal times = B.multiply(BigDecimal.valueOf(A));

    	System.out.println(times.longValue());
    }
}