import java.util.Scanner;

public class Reception {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int employeesOne = Integer.parseInt(scanner.nextLine());
        int employeesTwo = Integer.parseInt(scanner.nextLine());
        int employeesThree = Integer.parseInt(scanner.nextLine());

        int studentCount = Integer.parseInt(scanner.nextLine());

        double neededHours = 0;
        double answerPerHour = employeesOne + employeesTwo + employeesThree;

        while (studentCount > 0){
            studentCount -= answerPerHour;
            neededHours++;

            if (neededHours % 4 == 0) ;
            neededHours++;

            System.out.printf("Time needed: %f", answerPerHour);

        }
    }
}