You can use the same principle we just used to retrieve the last character in a string to retrieve the Nth-to-last character.

For example, you can get the value of the third-to-last letter of the var firstName = "Charles" string by using firstName[firstName.length - 3]

Instructions

Use bracket notation to find the second-to-last character in the lastName string.

Hint
Try looking at the thirdToLastLetterOfFirstName variable declaration if you get stuck.