Once upon a time, a common computer programming rule was that names of variables must be between

Question:

Once upon a time, a common computer programming rule was that names of variables must be between 1 and 8 characters long. The first character could be any of the 26 letters, while successive characters could be any of the 26 letters or any of the 10 digits. For example, allowable variable names were A, BBB, and M3477K. How many different variable names were possible?