I need to create a function that takes input a string containing a name in the "Last\_Name, First\_Name" format and prints a welcome message w/ first name first and the last name last and tells the person the length of their first name. The function should be able to handle a wrong input and print a message: Input format error: please use "Last\_Name, First\_Name". The below is what I have so far and the error I'm getting. I haven't been able to figure out how to create an error message if the user enters info in the wrong format:

```
input_name = input("Enter your name in last name, first name format")
Last_name, First_name =input_name.strip().split(',')
Full_name=First_name + ' ' + Last_name
print(Full_name + ' your first name is ' + len(First_name) + ' letters in length')

```

---

```none
TypeError
Traceback (most recent call last)
<ipython-input-14-14516c1daf2c> in <module>()
  2 Last_name, First_name =input_name.strip().split(',')
  3 Full_name=First_name + ' ' + Last_name
----> 4 print(Full_name + ' your first name is ' + len(First_name) + ' letters in length')
TypeError: can only concatenate str (not "int") to str

```