We said if this is, so this would be n, what's p equal to? p is equal to lambda divided by n, right? n times p is lambda, so let me just write that down. p is equal to lambda divided by n. I just rearranged this up here, right? So our probability of success is lambda times n. And we're saying, what's the probability that we have k successes? And then what's the probability that we have a failure? Well, it's 1 minus the probability of success.