import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    }
} import java.util.*; util.* java public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    } main {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    } 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 int c = (int)Math.round(100*b); c (int)Math.round(100*b) Math.round Math 100*b 100 b System.out.println((long)(a*c)/100) System.out.println System.out System System.out (long)(a*c)/100 (long)(a*c) a c 100 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();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    }
} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    }
} Main
import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();
        int c = (int)Math.round(100*b);
        System.out.println((long)(a*c)/100);
    }
}