Which instrument should I learn next?

I already know how to play piano and I am getting one this upcoming week, which iam excited about, its not one of the best pianos but it will do. My goal or dream was to learn three Instruments piano, violin, and cello, now that I learned one which one should I learn next? I am not going to start a new instrument right away, probably a year or two after the piano. I already have a few store in mind for the violin the place where I brought the piano has three violins for sale for a cheep price.