01. Softuni reception mid exam 05 07 2020

employer_1 = int(input())
employer_2 = int(input())
employer_3 = int(input())
count_of_students = int(input())
time_needed = 0
counter = 0
student_per_hour = int(employer_1 + employer_2 + employer_3)
while count_of_students > 0:
    count_of_students -= student_per_hour
    time_needed += 1
    if (time_needed - counter) % 3 == 0:
        time_needed += 1
        counter += 1
print(f'Time needed: {time_needed}h.')