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

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	}

} import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	}

} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	} main {
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal num1 = new BigDecimal(sc.next()); num1 new BigDecimal(sc.next()) BigDecimal num2 = new BigDecimal(sc.next()); num2 new BigDecimal(sc.next()) BigDecimal mul = num1.multiply(num2); mul num1.multiply(num2) num1.multiply num1 num2 BigDecimal result = mul.setScale(0, RoundingMode.DOWN); result mul.setScale(0, RoundingMode.DOWN) mul.setScale mul 0 RoundingMode.DOWN RoundingMode RoundingMode.DOWN long out = result.longValue(); out result.longValue() result.longValue result System.out.println(out) System.out.println System.out System System.out out sc.close() sc.close sc String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	}

} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	}

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

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		BigDecimal num1 = new BigDecimal(sc.next());
		BigDecimal num2 = new BigDecimal(sc.next());
		BigDecimal mul = num1.multiply(num2);
		BigDecimal result = mul.setScale(0, RoundingMode.DOWN);

		long out = result.longValue();


		System.out.println(out);
		sc.close();

	}

}