How do I create dynamic routes where the changing part is at the beginning of the path? I need to create custom module routes like the following.

/ireland-dummy-page (IE)
/uk-dummy-page (UK)
/dummy-page (global)

How can I write the route paths for this scenario? Do I want to write separate ones or is there any way to make this dynamic?
my.calculator:
  path: &quot;/{con}-dummy-page&quot;
  defaults:
    _controller: '\Drupal\calculator\Controller\CalculatorController::CalculatorPage'
    _title: &quot;Dummy test page&quot;
  requirements:
    _permission: &quot;access content&quot;
  options:
    no_cache: &quot;TRUE&quot;
In your edit, {con} is a route parameter? This is not possible in Drupal, you can't start with a route parameter and /{con}/ has to fill an entire route segment.
Before you can match a route for such a path you have to do some path processing. See Do new routes require a static first portion?