No Cambodia Phone Number Prefix in iCloud Keychain Setup?

Just updated to iOS 7.0.3 after the update completed, in the welcome screen when I tried to set up iCloud Keychain and it ask me for a phone number for identification, there is no Cambodia (+855) in the country code list. Now I am stuck there and the only option is leave the iCloud Keychain feature unused.

How could you forget a country? Please add Cambodia in asap, Apple.