Power of a two-sided test to catch a shift to 56

A test uses $H_0: \mu = 50$ against $H_1: \mu \neq 50$ with a known $\sigma = 10$, a sample of $n = 16$, at the two-sided 5% level. Suppose the true mean is actually $\mu = 56$.

Find the power of the test (the probability it correctly rejects $H_0$).