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

public class Main {
        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        }

} import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {
        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        }

} Main public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        } main {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String A = scan.next(); A scan.next() scan.next scan String B = scan.next(); B scan.next() scan.next scan BigDecimal bigA = new BigDecimal(A); bigA new BigDecimal(A) BigDecimal bigB = new BigDecimal(B); bigB new BigDecimal(B) BigDecimal seki = bigA.multiply(bigB); seki bigA.multiply(bigB) bigA.multiply bigA bigB BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN); outputmoto seki.setScale(0, BigDecimal.ROUND_DOWN) seki.setScale seki 0 BigDecimal.ROUND_DOWN BigDecimal BigDecimal.ROUND_DOWN long output = outputmoto.longValue()
; output outputmoto.longValue() outputmoto.longValue outputmoto System.out.println(output) System.out.println System.out System System.out output String[] args args public class Main {
        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        }

} public class Main {
        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        }

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

public class Main {
        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);

                String A = scan.next();
                String B = scan.next();
                
                BigDecimal bigA = new BigDecimal(A);
                BigDecimal bigB = new BigDecimal(B);
                
                BigDecimal seki = bigA.multiply(bigB);
                BigDecimal outputmoto = seki.setScale(0, BigDecimal.ROUND_DOWN);
                long output = outputmoto.longValue()
;
                System.out.println(output);

        }

}