import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  } main {
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long a = sc.nextLong(); a sc.nextLong() sc.nextLong sc int b = (int)(sc.nextDouble() * 100.00); b (int)(sc.nextDouble() * 100.00) sc.nextDouble() sc.nextDouble sc 100.00 long c = a * b / 100L; c a * b / 100L a * b a b 100L System.out.println(c) System.out.println System.out System System.out c String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  }
} Main
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	long a = sc.nextLong();
    int b = (int)(sc.nextDouble() * 100.00); 
  	long c = a * b / 100L;
    System.out.println(c);
  }
}