Write a program that prompts the user to enter the names of two primary colors, one at a time. If the user enters anything other than "red," "blue," or "yellow," the program should print "You didn't input two primary colors." Otherwise, it should print a message in the following format: "When you mix red and blue, you get purple." $($Assuming the user entered "red" and "blue$.)$

Look carefully at the following sample runs of the program. In particular, notice the wording of the messages and the placement of spaces, colons, and punctuation. Your program's output must match this.