Basic Instances

Josh has been asked to paint all the letterboxes on a given segment of a street, and he's curious about the street numbers. He realises that the street numbers are always a consecutive segment of numbers, and poses some problems from there.

Subtask 1 ($25\%$ of points)

How many times does the digit $6$ appear between $1$ and $678$?

Subtask 2 ($25\%$ of points)

How many numbers between $1$ and $678$ contain the digit $7$?

Subtask 3 ($25\%$ of points)

How many times does the digit $0$ appear between $6769$ and $41420$?

Subtask 4 ($25\%$ of points)

How many numbers between $15092025$ and $21092025$ contain the digit $9$?

Submission

Submit your answer to the subtasks as a comma-separated list of integers. For example, if your answers to the subtasks are $1, 0, 2$ and $4$, you should submit 1,0,2,4. Note that if you have not solved a subtask, you can submit a dummy answer for that subtask. For example, if your answer to the first subtask is $1$, you could submit 1,0,0,0.