A real estate office handles, say, 50 apartment units. When the rent is, say, $600 per month, all the units are occupied. However, for each, say, $40 increase in rent, one unit becomes vacant. Moreover, each occupied unit requires an average of $27 per month for maintenance. How many units should be rented to maximize the profit? Required:
Write a program that prompts the user to enter:

1. The total number of units.
2. The rent to occupy all the units.
3. The increase in rent that results in a vacant unit.
4. Amount to maintain a rented unit.

the today function returns a valid value without any arguments.

the today function returns the current date based on the computer's date setting and formatted as a date. today takes no parameters, but requires that you use empty parentheses

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