count_a = int(input())
count_b = int(input())
count_c = int(input())
people_count = int(input())

hours = 0
sum_per_hour = count_a + count_b + count_c

while people_count > 0:
    hours += 1
    people_count -= sum_per_hour
    if hours % 4 == 0:
        hours += 1
print(f"Time needed: {hours}h.")