import java.math.BigDecimal;
import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
      Scanner sc=new Scanner(System.in);
      String inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    }
} 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 inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    }
} Main public static void main(String[] args) {
      Scanner sc=new Scanner(System.in);
      String inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    } main {
      Scanner sc=new Scanner(System.in);
      String inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) String inp=sc.nextLine(); inp sc.nextLine() sc.nextLine sc String[] ip = inp.split(" "); ip inp.split(" ") inp.split inp " " String a = ip[0]; a ip[0] ip 0 String b = ip[1]; b ip[1] ip 1 BigDecimal c = new BigDecimal(a); c new BigDecimal(a) BigDecimal d = new BigDecimal(b); d new BigDecimal(b) BigDecimal res = c.multiply(d); res c.multiply(d) c.multiply c d long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue(); ans res.setScale(0, BigDecimal.ROUND_FLOOR).longValue() res.setScale(0, BigDecimal.ROUND_FLOOR).longValue res.setScale(0, BigDecimal.ROUND_FLOOR) res.setScale res 0 BigDecimal.ROUND_FLOOR BigDecimal BigDecimal.ROUND_FLOOR System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {

    public static void main(String[] args) {
      Scanner sc=new Scanner(System.in);
      String inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    }
} public class Main {

    public static void main(String[] args) {
      Scanner sc=new Scanner(System.in);
      String inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    }
} 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 inp=sc.nextLine();
      String[] ip = inp.split(" ");
      String a = ip[0];
      String b = ip[1];
      BigDecimal c = new BigDecimal(a);
      BigDecimal d = new BigDecimal(b);
      BigDecimal res = c.multiply(d);
      long ans = res.setScale(0, BigDecimal.ROUND_FLOOR).longValue();
      System.out.println(ans);
    }
}