Day 11: Merry Christmas "Ho"s

For the numbers 1 - 1,000,000:

• If the number is divisible by 6, append Merry Christmas to it
• If the number contains any 8s, then replace each 8 with a HO
• Otherwise just include the number

The result of each number is then concatenated.

Problem: How many digits are there in the number produced when summing the numbers produced when splitting the result string by non-digit characters?