Develop a c++ project with the following features:

1. Develop a function that takes an array of values and returns the highest value among the array. The function can take any data type that can use ">" or ">=" to compare values.

2. Write a function that can take the input from the keyboard. The input is a math expression with only + and - operations. The function returns the value of the calculation.

3. In your main function, create an array with 5 numbers. Ask the user to enter a value for each array element. Display the highest value among the 5 numbers by calling the function you developed in step 1.

4. Ask the user to enter an expression and display the result by calling the function you developed in step 2.

5. Get a sentence from the user such as "It is a good day". Display each word on a separate line.