Suppose identical tags are placed on both the left ear and the right ear of a fox. The fox is then let loose for a period of time. Consider the two events C1 = {left ear tag is lost} and C2 = {right ear tag is lost}. Let π = P(C1) = P(C2), and assume C1 and C2 are independent events. Derive an expression (involving π) for the probability that exactly one tag is lost, given that at most one is lost ("Ear Tag Loss in Red Foxes," J. Wildlife Mgmt., 1976: 164-167).