(our program must have function ma in, function presentValue, three read functions, and a display function. Including main this is six unctions. The presentValue function must have the following signature: double presentValue (double futureValue, double interestRate, int numberYears) The presentvalue needs to calculate the present value and return that back to the calling function. The formula for this is above. Note hat the annual interest would be .08 for 8%. Failure to follow the C++ requirements could reduce the points received from passing the tests. Seneral overview n part 2 you will be creating multiple functions to calculate the present value. (ou may be asking what a 'present value" is. Suppose you want to deposit a certain amount of money into a savings account and then save it alone to draw interest for some amount of time, say 12 years. At the end of the 12 years you want to have $15,000 in the account. The present value is the amount of money you would have to deposit today to have $15,000 in 12 years. The formula used needs the future value (F) and annual interest rate (r) and the number of years (n) the money will sit in the account, anchanged. You will be calculating the present value (P). > = F/ (1 +r)^n) n the above expression the value (1 + r) needs to be raised to the nth power. Assume that is the power function and x^2 is x to the 2nd power (x squared) rou are not allowed to use any global variables. Use of global variables will result in a grade of zero for part 2. Three read functions (ou must have functions to read in the future value, the annual interest rate, and the number of years. That would be three different unctions. Give these functions meaningful names. Note that the order of the values will be future value, annual interest rate, and number of ears. n all cases you need to return any valid value back to the calling function. For all three functions you will write out to cout as prompt for an input value. You will read in that value from cin. If the value is invalid zero or negative) you need to display an error message and reread the value (with another prompt). You need to do this in a loop and continue looping until a valid value has been entered. Only the number of years can be an snt value. The rest should be of type double. tere are the prompts for the three values you need to read in: Enter future value Enter annual interest rate Enter number of years Note that the interest rate will be a number such as 10 or 12.5. These are to be read in as percentages (10% and 12.5%). You will need to ivide these values by 100 to convert them into the values needed in the function (,1 and.125 for the above values). This conversion needs o be done before you call the presentValue function (see below). If you do the conversion in the presentValue function your orogram will failthe unit tests, so do the conversion before you call the calculate function. Here are the error messages you need to display if the values are negative: