import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Scanner;
// A - Multiplication 1
class Main{
	public static void main(String[] args){

		Scanner sc = new Scanner(System.in);
		BigDecimal A = sc.nextBigDecimal();

		BigDecimal B = sc.nextBigDecimal();

		BigDecimal w = A.multiply(B);

		BigDecimal ans = w.setScale(0, RoundingMode.DOWN);


		System.out.println(ans);
	}
} import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.Scanner; Scanner java.util class Main{
	public static void main(String[] args){

		Scanner sc = new Scanner(System.in);
		BigDecimal A = sc.nextBigDecimal();

		BigDecimal B = sc.nextBigDecimal();

		BigDecimal w = A.multiply(B);

		BigDecimal ans = w.setScale(0, RoundingMode.DOWN);


		System.out.println(ans);
	}
} Main public static void main(String[] args){

		Scanner sc = new Scanner(System.in);
		BigDecimal A = sc.nextBigDecimal();

		BigDecimal B = sc.nextBigDecimal();

		BigDecimal w = A.multiply(B);

		BigDecimal ans = w.setScale(0, RoundingMode.DOWN);


		System.out.println(ans);
	} main {

		Scanner sc = new Scanner(System.in);
		BigDecimal A = sc.nextBigDecimal();

		BigDecimal B = sc.nextBigDecimal();

		BigDecimal w = A.multiply(B);

		BigDecimal ans = w.setScale(0, RoundingMode.DOWN);


		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal A = sc.nextBigDecimal(); A sc.nextBigDecimal() sc.nextBigDecimal sc BigDecimal B = sc.nextBigDecimal(); B sc.nextBigDecimal() sc.nextBigDecimal sc BigDecimal w = A.multiply(B); w A.multiply(B) A.multiply A B BigDecimal ans = w.setScale(0, RoundingMode.DOWN); ans w.setScale(0, RoundingMode.DOWN) w.setScale w 0 RoundingMode.DOWN RoundingMode RoundingMode.DOWN System.out.println(ans) System.out.println System.out System System.out ans String[] args args
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Scanner;
// A - Multiplication 1
class Main{
	public static void main(String[] args){

		Scanner sc = new Scanner(System.in);
		BigDecimal A = sc.nextBigDecimal();

		BigDecimal B = sc.nextBigDecimal();

		BigDecimal w = A.multiply(B);

		BigDecimal ans = w.setScale(0, RoundingMode.DOWN);


		System.out.println(ans);
	}
}