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

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  }
} import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  } main {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal a = new BigDecimal(sc.next()); a new BigDecimal(sc.next()) BigDecimal b = new BigDecimal(sc.next()); b new BigDecimal(sc.next()) System.out.println(a.multiply(b).toBigInteger()) System.out.println System.out System System.out a.multiply(b).toBigInteger() a.multiply(b).toBigInteger a.multiply(b) a.multiply a b String[] args args public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  }
} public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  }
} Main
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    BigDecimal a = new BigDecimal(sc.next());
    BigDecimal b = new BigDecimal(sc.next());
    System.out.println(a.multiply(b).toBigInteger());
  }
}