Exercise 1 Write a PHP script that prompts the user to enter several positive integer numbers and store them in an array, when the user is done, he/she should enter a negative value. Then you should calculate the summation and the product of the array elements. Exercise 2 Write a php script that contains a function that takes a string, then it prints each word of this string alone. (Hint: try to deal with the string as an array of characters, and consider the space is the word separator). What files to Submit A php file for each exercise