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).toString().split("\\."))[0]);
    }
} 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).toString().split("\\."))[0]);
    }
} 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).toString().split("\\."))[0]);
    } 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).toString().split("\\."))[0]);
    } 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).toString().split("\\."))[0]) System.out.println System.out System System.out (A.multiply(B).toString().split("\\."))[0] (A.multiply(B).toString().split("\\.")) A.multiply(B).toString().split A.multiply(B).toString() A.multiply(B).toString A.multiply(B) A.multiply A B "\\." 0 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).toString().split("\\."))[0]);
    }
} 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).toString().split("\\."))[0]);
    }
} 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).toString().split("\\."))[0]);
    }
}