# Phone Number

Clean up user-entered phone numbers so that they can be sent SMS messages.

The **North American Numbering Plan (NANP)** is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda. All NANP-countries share the same international country code: `1`.

NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as *area code*, followed by a seven-digit local number. The first three digits of the local number represent the *exchange code*, followed by the unique four-digit number which is the *subscriber number*.

The format is usually represented as

```text
(NXX)-NXX-XXXX
```

where `N` is any digit from 2 through 9 and `X` is any digit from 0 through 9.

Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code (1) if present.

For example, the inputs
- `+1 (613)-995-0253`
- `613-995-0253`
- `1 613 995 0253`
- `613.995.0253`

should all produce the output

`6139950253`

**Note:** As this exercise only deals with telephone numbers used in NANP-countries, only 1 is considered a valid country code.

## Running tests

Execute the tests with:

```bash
$ elixir phone_number_test.exs
```

### Pending tests

In the test suites, all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by
commenting out the relevant `@tag :pending` with a `#` symbol.

For example:

```elixir
# @tag :pending
test "shouting" do
  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end
```

Or, you can enable all the tests by commenting out the
`ExUnit.configure` line in the test suite.

```elixir
# ExUnit.configure exclude: :pending, trace: true
```

For more detailed information about the Elixir track, please
see the [help page](http://exercism.io/languages/elixir).

## Source

Event Manager by JumpstartLab [http://tutorials.jumpstartlab.com/projects/eventmanager.html](http://tutorials.jumpstartlab.com/projects/eventmanager.html)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.