

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

public class Main {

	public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	}

} import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	}

} Main public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	} main {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	} Scanner scanner=new Scanner(System.in); scanner new Scanner(System.in) BigDecimal a = BigDecimal.valueOf(scanner.nextLong()); a BigDecimal.valueOf(scanner.nextLong()) BigDecimal.valueOf BigDecimal scanner.nextLong() scanner.nextLong scanner BigDecimal b = BigDecimal.valueOf(scanner.nextDouble()); b BigDecimal.valueOf(scanner.nextDouble()) BigDecimal.valueOf BigDecimal scanner.nextDouble() scanner.nextDouble scanner System.out.println(a.multiply(b).longValue()) System.out.println System.out System System.out a.multiply(b).longValue() a.multiply(b).longValue a.multiply(b) a.multiply a b scanner.close() scanner.close scanner String[] args args public class Main {

	public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	}

} public class Main {

	public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	}

} Main


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

public class Main {

	public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);

		BigDecimal a = BigDecimal.valueOf(scanner.nextLong());
		BigDecimal b = BigDecimal.valueOf(scanner.nextDouble());
		System.out.println(a.multiply(b).longValue());



		scanner.close();

	}

}
