import java.util.Scanner;
import java.math.BigDecimal;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    }
} 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);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    } main {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal a = sc.nextBigDecimal(); a sc.nextBigDecimal() sc.nextBigDecimal sc double b = sc.nextDouble(); b sc.nextDouble() sc.nextDouble sc sc.close() sc.close sc BigDecimal ans = a.multiply(BigDecimal.valueOf(b)); ans a.multiply(BigDecimal.valueOf(b)) a.multiply a BigDecimal.valueOf(b) BigDecimal.valueOf BigDecimal b System.out.println(ans.longValue()) System.out.println System.out System System.out ans.longValue() ans.longValue ans String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    }
} Main
import java.util.Scanner;
import java.math.BigDecimal;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = sc.nextBigDecimal();
        double b = sc.nextDouble();
        sc.close();
 
        BigDecimal ans = a.multiply(BigDecimal.valueOf(b));
        System.out.println(ans.longValue());
    }
}
