Decode the Secret Message

This problem is part of solulu Pro

A message of digits encodes letters as A=1, B=2, …, Z=26. For example "11106" can be read as "AAJF" (1 1 10 6) or "KJF" (11 10 6). A leading zero is invalid ("06" ≠ "F"). How many different ways can the digit string be…