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