import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        }

    }
} Main public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) Task solver = new Task(); solver new Task() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class Task
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        }

    } Task public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        } solve {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        } BigDecimal a = new BigDecimal("" + in.nextDouble()); a new BigDecimal("" + in.nextDouble()) BigDecimal b = new BigDecimal("" + in.nextDouble()); b new BigDecimal("" + in.nextDouble()) out.println(a.multiply(b).toBigInteger()) out.println out a.multiply(b).toBigInteger() a.multiply(b).toBigInteger a.multiply(b) a.multiply a b int testNumber testNumber Scanner in in PrintWriter out out public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        }

    }
} public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            BigDecimal a = new BigDecimal("" + in.nextDouble());
            BigDecimal b = new BigDecimal("" + in.nextDouble());
            out.println(a.multiply(b).toBigInteger());
        }

    }
}

