Similarly to other "bounded error" probabilistic classes the choice of 1/3 in the definition is arbitrary. We can run the algorithm a constant number of times and take a majority vote to achieve any desired probability of correctness less than 1, using the Chernoff bound. The complexity class is unchanged by allowing error as high as 1/2 − "n"−"c" on the one hand, or requiring error as small as 2−"nc" on the other hand, where "c" is any positive constant, and "n" is the length of input.