_{NOTE - Branch reset group is supported by Perl, PHP, Delphi and R.}

A branch reset group consists of alternations and capturing groups. (?|(regex1)|(regex2))
Alternatives in branch reset group share same capturing group.

Task

You have a test string .
Your task is to write a regex which will match , with following condition(s):

• consists of 8 digits.
• must have "---", "-", "." or ":" separator such that string gets divided in parts, with each part having exactly two digits.
• string must have exactly one kind of separator.
• Separators must have integers on both sides.

Valid

12-34-56-78
12:34:56:78
12---34---56---78
12.34.56.78

Invalid

1-234-56-78
12-45.78:10

Note

This is a regex only challenge. You are not required to write any code.
You only have to fill the regex pattern in the blank (_________).