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

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).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 scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).longValue());
	}
} Main public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).longValue());
	} main {

		Scanner scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).longValue());
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String in[] =  scan.nextLine().split(" "); in scan.nextLine().split(" ") scan.nextLine().split scan.nextLine() scan.nextLine scan " " BigDecimal A =  new BigDecimal(in[0]); A new BigDecimal(in[0]) BigDecimal B = new BigDecimal(in[1]); B new BigDecimal(in[1]) 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 String[] args args public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).longValue());
	}
} public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).longValue());
	}
} Main
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String in[] =  scan.nextLine().split(" ");
		BigDecimal A =  new BigDecimal(in[0]);
		BigDecimal B = new BigDecimal(in[1]);

		System.out.println(A.multiply(B).longValue());
	}
}