import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    }
} 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);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    } main {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long A = sc.nextLong(); A sc.nextLong() sc.nextLong sc double B = sc.nextDouble(); B sc.nextDouble() sc.nextDouble sc BigDecimal a = new BigDecimal(String.valueOf(A)); a new BigDecimal(String.valueOf(A)) BigDecimal b = new BigDecimal(String.valueOf(B)); b new BigDecimal(String.valueOf(B)) BigDecimal result = a.multiply(b); result a.multiply(b) a.multiply a b System.out.println(result.longValue()) System.out.println System.out System System.out result.longValue() result.longValue result String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    }
} Main
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextLong();
        double B = sc.nextDouble();
        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));
        BigDecimal result = a.multiply(b);
        System.out.println(result.longValue());
    }
}