import java.util.Scanner;

/*

*/

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

        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    }
} import java.util.Scanner; Scanner 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();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    }
} Main public static void main(String[] args){

        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    } main {

        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    } 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 long std = a; std a if (a >= 100) {
        	a = a/100;
        } a >= 100 a 100 {
        	a = a/100;
        } a = a/100 a a/100 a 100 double ans = Math.floor(a * b); ans Math.floor(a * b) Math.floor Math a * b a b if (std >= 100) {
        	ans = ans*100;
        } std >= 100 std 100 {
        	ans = ans*100;
        } ans = ans*100 ans ans*100 ans 100 System.out.println((long)ans) System.out.println System.out System System.out (long)ans 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();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

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

        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    }
} Main
import java.util.Scanner;

/*

*/

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

        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    }
}