import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long a = sc.nextLong();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(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();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(ans);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long a = sc.nextLong();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(ans);
    } main {
        Scanner sc = new Scanner(System.in);

        long a = sc.nextLong();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(ans);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long a = sc.nextLong(); a sc.nextLong() sc.nextLong sc String b = sc.next(); b sc.next() sc.next sc long b0 = (b.charAt(0) - '0') * 100; b0 (b.charAt(0) - '0') * 100 (b.charAt(0) - '0') b.charAt(0) b.charAt b 0 '0' 100 long b1 = (b.charAt(2) - '0') * 10; b1 (b.charAt(2) - '0') * 10 (b.charAt(2) - '0') b.charAt(2) b.charAt b 2 '0' 10 long b2 = b.charAt(3) - '0'; b2 b.charAt(3) - '0' b.charAt(3) b.charAt b 3 '0' long ans = (a * b0 + a * b1 + a * b2) / 100; ans (a * b0 + a * b1 + a * b2) / 100 (a * b0 + a * b1 + a * b2) a * b0 + a * b1 + a * b2 a * b0 a b0 a * b1 a b1 a * b2 a b2 100 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long a = sc.nextLong();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(ans);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long a = sc.nextLong();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(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();
        // 1 double b = sc.nextDouble();
        String b = sc.next();

        // 1 long ans = (long)(a*b);

        // 2 long b0 = b.charAt(0) - '0';
        // 2 long b1 = b.charAt(2) - '0';
        // 2 long b2 = b.charAt(3) - '0';

        // 2 long ans = a * b0 + a * b1 / 10 + a * b2 / 100;

        long b0 = (b.charAt(0) - '0') * 100;
        long b1 = (b.charAt(2) - '0') * 10;
        long b2 = b.charAt(3) - '0';

        long ans = (a * b0 + a * b1 + a * b2) / 100;

        System.out.println(ans);
    }
}