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

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