//q2
import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        Integer i=Integer.parseInt(sc.nextLine());
        String nameofevent=sc.nextLine();
        String eventdetail=sc.nextLine();
        String type=sc.nextLine();
        String owner=sc.nextLine();
        double costperday=sc.nextDouble();
        int num=sc.nextInt();
        sc.nextLine();
        String d1=sc.nextLine();
        String d2=sc.nextLine();
        d1=d1.substring(0,2);
        d2=d2.substring(0,2);
        int num1=Integer.parseInt(d1);
        int num2=Integer.parseInt(d2);
        int diff=num2-num1;
        if (i==1){
            double tot=diff*costperday;
            tot=tot*(5d/100d);
            System.out.println(tot);
            
        }
        else{
            double tot=diff*costperday;
            System.out.println(tot*(15d/100d));
        }
    }
}