import java.math.BigDecimal;
import java.math.RoundingMode;
import 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());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    }
} import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.*; util.* java 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());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    }
} 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());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    } main {
        Scanner sc = new Scanner(System.in);
        BigDecimal a = new BigDecimal(sc.next());
        BigDecimal b = new BigDecimal(sc.next());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    } 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()) a = a.multiply(b) a a.multiply(b) a.multiply a b System.out.println(a.longValue()) System.out.println System.out System System.out a.longValue() a.longValue a 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());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    }
} 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());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    }
} Main
import java.math.BigDecimal;
import java.math.RoundingMode;
import 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());
        a = a.multiply(b);
        
        System.out.println(a.longValue());
    }
}
