import java.util.Scanner;

public class Main {
	public void main(Scanner sc) {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public void main(Scanner sc) {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	}
} Main public void main(Scanner sc) {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	} main {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	} long a = sc.nextLong(); a sc.nextLong() sc.nextLong sc long b = new Long(sc.next().replace(".", "")); b new Long(sc.next().replace(".", "")) String ans = new Long(a * b).toString(); ans new Long(a * b).toString() new Long(a * b).toString new Long(a * b) if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		} ans.length() >= 3 ans.length() ans.length ans 3 {
			System.out.println(ans.substring(0, ans.length() - 2));
		} System.out.println(ans.substring(0, ans.length() - 2)) System.out.println System.out System System.out ans.substring(0, ans.length() - 2) ans.substring ans 0 ans.length() - 2 ans.length() ans.length ans 2 {
			System.out.println(0);
		} System.out.println(0) System.out.println System.out System System.out 0 Scanner sc sc public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	} main {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) new Main().main(sc) new Main().main new Main() sc String[] args args public class Main {
	public void main(Scanner sc) {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	}
} public class Main {
	public void main(Scanner sc) {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	}
} Main
import java.util.Scanner;

public class Main {
	public void main(Scanner sc) {
		long a = sc.nextLong();
		long b = new Long(sc.next().replace(".", ""));

		String ans = new Long(a * b).toString();

		if (ans.length() >= 3) {
			System.out.println(ans.substring(0, ans.length() - 2));
		} else {
			System.out.println(0);
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		new Main().main(sc);
	}
}
