Find duplicates in string

Hi,

I've got the string:
123(05)-333(12)-2354(13)-2354(14)-3333(50)
And I need a script to remove duplicated numbers from the string, but with ignoring the brackets. In this case from string above should be removed '-2354(14)'
I know I need to explode the string by '-' first, but what next?

Thanks for any help.