import java.util.*;
import java.io.*;

public class Main
{
	public static void main(String [] Args)
	{
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	}
}
	 import java.util.*; util.* java import java.io.*; io.* java public class Main
{
	public static void main(String [] Args)
	{
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	}
} Main public static void main(String [] Args)
	{
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	} main {
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	} long ans=1; ans 1 int flag=0; flag 0 Scanner in = new Scanner(System.in); in new Scanner(System.in) long a=in.nextLong(); a in.nextLong() in.nextLong in String b=in.next(); b in.next() in.next in ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0') ans a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0') a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0') a*(b.charAt(0)-'0')*100 a*(b.charAt(0)-'0')*100 a (b.charAt(0)-'0') b.charAt(0) b.charAt b 0 '0' 100 a*(b.charAt(2)-'0')*10 a*(b.charAt(2)-'0')*10 a (b.charAt(2)-'0') b.charAt(2) b.charAt b 2 '0' 10 a*(b.charAt(3)-'0') a (b.charAt(3)-'0') b.charAt(3) b.charAt b 3 '0' System.out.println(ans/100) System.out.println System.out System System.out ans/100 ans 100 String [] Args Args public class Main
{
	public static void main(String [] Args)
	{
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	}
} public class Main
{
	public static void main(String [] Args)
	{
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	}
} Main
import java.util.*;
import java.io.*;

public class Main
{
	public static void main(String [] Args)
	{
		long ans=1;
		int flag=0;
		Scanner in = new Scanner(System.in);
		long a=in.nextLong();
		String b=in.next();
		ans=a*(b.charAt(0)-'0')*100+a*(b.charAt(2)-'0')*10+a*(b.charAt(3)-'0');
		System.out.println(ans/100);
	}
}
	