import re


def IsZone(zone_or_region):
  """Returns whether "zone_or_region" is a zone.

  Args:
    zone_or_region: string, Azure zone or region. Format for Azure
      availability
      zone support is "region-availability_zone". Example: eastus2-1 specifies
        Azure region eastus2 with availability zone 1.
  """

  return re.match(r'[a-z]+[0-9]?-[0-9]$', zone_or_region)