import java.math.BigDecimal;
import java.util.Scanner;
 
public class Main {    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        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 a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc BigDecimal abi = new BigDecimal(a); abi new BigDecimal(a) String b = sc.next(); b sc.next() sc.next sc BigDecimal bbi = new BigDecimal(b); bbi new BigDecimal(b) BigDecimal ans = abi.multiply(bbi); ans abi.multiply(bbi) abi.multiply abi bbi long pri = ans.longValue(); pri ans.longValue() ans.longValue ans System.out.println(pri) System.out.println System.out System System.out pri sc.close() sc.close sc String[] args args public class Main {    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        sc.close();
    }
} public class Main {    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        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 a = sc.next();
        BigDecimal abi = new BigDecimal(a);
        String b = sc.next();
        BigDecimal bbi = new BigDecimal(b);
        BigDecimal ans = abi.multiply(bbi);
        long pri = ans.longValue();

        System.out.println(pri);
        sc.close();
    }
}