Let X0 be the amount of rain that will fall in the United States on the next Christmas day. For n > 0, let Xn be the amount of rain that will fall in the United States on Christmas n years later. Let N be the smallest number of years that elapse before we get a Christmas rainfall greater than X0. Suppose that P(Xi = Xj) = 0 if i 6= j, the events concerning the amount of rain on Christmas days of different years are all independent, and the Xn’s are identically distributed. Find the expected value of N.