import java.util.*;
import java.math.BigDecimal;
public class Main {
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  }
}   import java.util.*; util.* java 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();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  }
} Main public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  } main {
    Scanner sc = new Scanner(System.in);
    BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal A = sc.nextBigDecimal(); A sc.nextBigDecimal() sc.nextBigDecimal sc BigDecimal B = sc.nextBigDecimal(); B sc.nextBigDecimal() sc.nextBigDecimal sc BigDecimal ans = A.multiply(B); ans A.multiply(B) A.multiply A B System.out.println(ans.toBigInteger()) System.out.println System.out System System.out ans.toBigInteger() ans.toBigInteger ans String args[] args public class Main {
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  }
} public class Main {
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  }
} Main
import java.util.*;
import java.math.BigDecimal;
public class Main {
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();		
		BigDecimal ans = A.multiply(B);
		System.out.println(ans.toBigInteger());
  }
}  