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

public class Main {
    public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    }
} import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    }
} Main public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    } main {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) BigDecimal A = new BigDecimal(in.next()); A new BigDecimal(in.next()) BigDecimal B = new BigDecimal(in.next()); B new BigDecimal(in.next()) BigDecimal a = A.multiply(B); a A.multiply(B) A.multiply A B long answer = a.longValue(); answer a.longValue() a.longValue a System.out.println(answer) System.out.println System.out System System.out answer String[] args args public class Main {
    public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    }
} public class Main {
    public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    }
} Main
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
      
        BigDecimal A = new BigDecimal(in.next());
        BigDecimal B = new BigDecimal(in.next());
		BigDecimal a = A.multiply(B);
        long answer = a.longValue();
        System.out.println(answer);
    }
}