It's like roughly 6.9% chance that you get the unfair coin and then get four heads in a row. The probability that you get the fair coin and then get four heads in a row is even lower. It's only a 1.6% chance. Now, the probability of getting four heads in a row either way is going to be the sum of this and this, or the sum of that and that, which is going to be. Let me keep my calculator out. So it's going to be equal to. I can just take the previous answer.