import java.util.Scanner;


public class Main {
		public static void main (String args[]) throws Exception{
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	}
} import java.util.Scanner; Scanner java.util public class Main {
		public static void main (String args[]) throws Exception{
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	}
} Main public static void main (String args[]) throws Exception{
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	} main {
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long a = scan.nextLong(); a scan.nextLong() scan.nextLong scan String b = scan.next(); b scan.next() scan.next scan b = b.replace(".", "") b b.replace(".", "") b.replace b "." "" long f = Long.parseLong(b.substring(0, 1)) * a * 100; f Long.parseLong(b.substring(0, 1)) * a * 100 Long.parseLong(b.substring(0, 1)) * a * 100 Long.parseLong(b.substring(0, 1)) Long.parseLong Long b.substring(0, 1) b.substring b 0 1 a 100 long s  = Long.parseLong(b.substring(1, 2)) * a * 10; s Long.parseLong(b.substring(1, 2)) * a * 10 Long.parseLong(b.substring(1, 2)) * a * 10 Long.parseLong(b.substring(1, 2)) Long.parseLong Long b.substring(1, 2) b.substring b 1 2 a 10 long t = Long.parseLong(b.substring(2, 3)) * a; t Long.parseLong(b.substring(2, 3)) * a Long.parseLong(b.substring(2, 3)) Long.parseLong Long b.substring(2, 3) b.substring b 2 3 a long temp = f + s + t; temp f + s + t f + s + t f s t long ans =  (temp) /100; ans (temp) /100 (temp) 100 System.out.println(ans) System.out.println System.out System System.out ans String args[] args public class Main {
		public static void main (String args[]) throws Exception{
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	}
} public class Main {
		public static void main (String args[]) throws Exception{
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	}
} Main
import java.util.Scanner;


public class Main {
		public static void main (String args[]) throws Exception{
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		String b = scan.next();
		b = b.replace(".", "");
		long f = Long.parseLong(b.substring(0, 1)) * a * 100;
		long s  = Long.parseLong(b.substring(1, 2)) * a * 10;
		long t = Long.parseLong(b.substring(2, 3)) * a;
		long temp = f + s + t; 
		// seisuu
		long ans =  (temp) /100;
		System.out.println(ans);
	}
}