Create a function that takes the number of daily average recovered cases recovers, daily average new_cases, current active_cases, and returns the number of days it will take to reach zero cases.
end_corona(4000, 2000, 77000) ➞ 39
end_corona(3000, 2000, 50699) ➞ 51
end_corona(30000, 25000, 390205) ➞ 79
recovers will always be greater than daily new_cases.