 There's one other thing you need to know about the join method. The list that you give it must be a list of strings. Here's a list of integers. If we try to do something like this, and use a dash to join the list of integers, and then print the result, when we run it, we'll get a type error. Join is expecting a string list, not an integer list. When you need to join a list of numbers, you'll need to convert it to a list of strings. Let's write a function to do that. Let's first clear out our shell, and give ourselves a little bit more room to see the code. We'll define a function called stringify that expects a number list as its parameter. We'll create a result list as the empty list, and then for each item in the number list, we're going to take the result list and append what we get from using the stir function to convert the item to a string. When the loop is done, we can return the result list. Now let's use that function that we just wrote. Our day-month-year string list will be the result of calling stringify with the list of integers. We're still going to do join, but we're going to now join the day-month-year string list because those will all be strings, and the program will work. That's the extra cautionary note you need to know when you use join.