import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;
 
public class Main {
 
   private static int daysFromMillis(long millis) {
      return (int) (millis / 86400000);
   }
 
   public static void main(String args[]) throws ParseException {
      Scanner sc = new Scanner(System.in);
      DateFormat format = new SimpleDateFormat("dd/MM/yyyy");
      System.out.print("Enter start date (dd/mm/yyyy):\n> ");
      Date dateStart = format.parse(sc.nextLine());
      System.out.print("Enter end date (dd/mm/yyyy):\n> ");
      Date dateEnd = format.parse(sc.nextLine());
      System.out.print("Enter amount:\n>  ");
      System.out.println("Average revenue:\n< "
            + (sc.nextDouble() / daysFromMillis(dateEnd.getTime()
                  - dateStart.getTime())));
 
   }
}