Enter DASH after TRIM

Hello:
I have this in a cell:
13 2

I used the TRIM command and made it:

13 2



But now I need to add a dash between the 13 and the 2, so that it will look like this : 13-2


i have over 1,000 parcels to do this to.

Please tell me how to do it, I need it asap. I dont know what the command/formula is after I have trimmed it.. Thanks !!