import java.util.*;
public class emp{
    public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
float sal=sc.nextFloat();
    int exp=sc.nextInt();
    if(n<0){
        System.out.println("Invalid input");
    }
    else if(exp<2){
        System.out.println(sal);
    }
    else if(exp>=2 && exp<=5)
    {
        sal=sal/20;
        System.out.printf("%.1f",sal);
    }
    else
    {
        sal=sal%100;
        System.out.printf("%.1f",sal);
    }
}}