
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    } main {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) final long A = sc.nextLong(); A sc.nextLong() sc.nextLong sc final float B = sc.nextFloat(); B sc.nextFloat() sc.nextFloat sc long b = (long) ((B+0.0001f) * 100 / 1); b (long) ((B+0.0001f) * 100 / 1) (B+0.0001f) * 100 (B+0.0001f) B 0.0001f 100 1 System.out.println(A * b / 100) System.out.println System.out System System.out A * b / 100 A * b A b 100 String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    }
} Main

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        final long A = sc.nextLong();
        final float B = sc.nextFloat();
        long b = (long) ((B+0.0001f) * 100 / 1);
        System.out.println(A * b / 100);
    }
}
