Well, it's going to be the probability of getting the fair coin, which is 1 third, times the probability of getting 4 out of 6 heads given the fair coin. And that's this, 15 over 64, plus the probability of getting an unfair coin, 2 thirds, times the probability of getting 4 out of 6 heads given the unfair coin. And that's what we figured out here. Times 15 times 0.8 to the fourth times 0.2 squared. And this is the probability of getting 4 out of 6 heads. And let's figure out what that is. Well, this will cancel out with this.