`A message containing letters from A-Z is being encoded to numbers using the following mapping:`

'A' -> 1

'B' -> 2

...

'Z' -> 26

Given an encoded message containing digits, determine the total number of ways to decode it.

`How about empty message?`

In the right solution, it's `0`

which is not clearly clarified in the problem description. I really think this not a good one. What do you think about it? @Global-Moderators @administrators