Write a C program that defines a function called 'multiply_by_two' that takes an integer as an argument and returns the result of multiplying it by 2 . The main function of the program should prompt the user to enter an integer, call the 'multiply_by_two' function with the user-entered integer as an argument, and then print out the result returned by the function. In addition to the basic functionality described above, the program should also have the following features:The program should continue to prompt the user for integers and perform the multiplication until the user enters a negative number