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

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

		System.out.println(x.multiply(BigDecimal.valueOf(a)).longValue());
	}

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

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

		System.out.println(x.multiply(BigDecimal.valueOf(a)).longValue());
	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

		System.out.println(x.multiply(BigDecimal.valueOf(a)).longValue());
	} main {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

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

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

		System.out.println(x.multiply(BigDecimal.valueOf(a)).longValue());
	}

} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

		System.out.println(x.multiply(BigDecimal.valueOf(a)).longValue());
	}

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

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		double b = sc.nextDouble();

		BigDecimal x = BigDecimal.valueOf(b);
		x.multiply(BigDecimal.valueOf(a));

		System.out.println(x.multiply(BigDecimal.valueOf(a)).longValue());
	}

}
