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

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    }
} import java.math.RoundingMode; RoundingMode java.math import java.util.Scanner; Scanner java.util import java.math.BigDecimal; BigDecimal java.math public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    } main {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long a = sc.nextLong(); a sc.nextLong() sc.nextLong sc double b = sc.nextDouble(); b sc.nextDouble() sc.nextDouble sc BigDecimal bd1 = BigDecimal.valueOf(a); bd1 BigDecimal.valueOf(a) BigDecimal.valueOf BigDecimal a BigDecimal bd2 = BigDecimal.valueOf(b); bd2 BigDecimal.valueOf(b) BigDecimal.valueOf BigDecimal b BigDecimal bd3 = bd1.multiply(bd2); bd3 bd1.multiply(bd2) bd1.multiply bd1 bd2 BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN); sol bd3.setScale(0, RoundingMode.DOWN) bd3.setScale bd3 0 RoundingMode.DOWN RoundingMode RoundingMode.DOWN System.out.println(sol) System.out.println System.out System System.out sol String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    }
} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    }
} Main
import java.math.RoundingMode;
import java.util.Scanner;
import java.math.BigDecimal;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        BigDecimal bd1 = BigDecimal.valueOf(a);
        BigDecimal bd2 = BigDecimal.valueOf(b);
        BigDecimal bd3 = bd1.multiply(bd2);
        BigDecimal sol = bd3.setScale(0, RoundingMode.DOWN);

        System.out.println(sol);
    }
}