import java.math.BigDecimal;
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());
        System.out.println(A.multiply(B).longValue());
    }
} import java.math.BigDecimal; BigDecimal 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());
        System.out.println(A.multiply(B).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());
        System.out.println(A.multiply(B).longValue());
    } 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).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()) System.out.println(A.multiply(B).longValue()) System.out.println System.out System System.out A.multiply(B).longValue() A.multiply(B).longValue 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);
        BigDecimal A = new BigDecimal(sc.next());
        BigDecimal B = new BigDecimal(sc.next());
        System.out.println(A.multiply(B).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());
        System.out.println(A.multiply(B).longValue());
    }
} Main
import java.math.BigDecimal;
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());
        System.out.println(A.multiply(B).longValue());
    }
}