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

public class Main {
    public static void main(String... args) {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    }
} import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String... args) {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    }
} Main public static void main(String... args) {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    } main {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long A = scan.nextLong(); A scan.nextLong() scan.nextLong scan double B = scan.nextDouble(); B scan.nextDouble() scan.nextDouble scan BigDecimal a = BigDecimal.valueOf(A); a BigDecimal.valueOf(A) BigDecimal.valueOf BigDecimal A BigDecimal b = BigDecimal.valueOf(B); b BigDecimal.valueOf(B) BigDecimal.valueOf BigDecimal B System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR)) System.out.println System.out System System.out a.multiply(b).setScale(0, RoundingMode.FLOOR) a.multiply(b).setScale a.multiply(b) a.multiply a b 0 RoundingMode.FLOOR RoundingMode RoundingMode.FLOOR String... args args public class Main {
    public static void main(String... args) {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    }
} public class Main {
    public static void main(String... args) {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    }
} Main
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Scanner;

public class Main {
    public static void main(String... args) {
        Scanner scan = new Scanner(System.in);
        long A = scan.nextLong();
        double B = scan.nextDouble();
        BigDecimal a = BigDecimal.valueOf(A);
        BigDecimal b = BigDecimal.valueOf(B);
        System.out.println(a.multiply(b).setScale(0, RoundingMode.FLOOR));
    }
}
