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


public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	}

} 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);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	}

} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	} main {

		Scanner sc = new Scanner(System.in);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	} 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 culc = a.multiply(b); culc a.multiply(b) a.multiply a b long ans = culc.longValue(); ans culc.longValue() culc.longValue culc System.out.println(ans) System.out.println System.out System System.out ans sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	}

} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	}

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


public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		BigDecimal a = sc.nextBigDecimal();
		BigDecimal b = sc.nextBigDecimal();
		
		BigDecimal culc = a.multiply(b);
		long ans = culc.longValue();
		System.out.println(ans);
		sc.close();
	}

}