

import java.util.*; 
import java.math.*;
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());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	}
 
} import java.util.*; util.* java import java.math.*; math.* 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());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	}
 
} 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());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	} main {
		Scanner sc = new Scanner(System.in);
		BigDecimal a = new BigDecimal(sc.next());
		BigDecimal b = new BigDecimal(sc.next());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	} 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()) BigDecimal c = a.multiply(b); c a.multiply(b) a.multiply a b BigDecimal d = c.setScale(0,RoundingMode.FLOOR); d c.setScale(0,RoundingMode.FLOOR) c.setScale c 0 RoundingMode.FLOOR RoundingMode RoundingMode.FLOOR System.out.println(d) System.out.println System.out System System.out d sc.close() sc.close sc 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());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	}
 
} 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());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	}
 
} Main


import java.util.*; 
import java.math.*;
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());
		BigDecimal c = a.multiply(b);
		BigDecimal d = c.setScale(0,RoundingMode.FLOOR);
		System.out.println(d);
		sc.close();
	}
 
}