Consider a meeting of n businessmen sitting around a circular table. To start the meeting, they must shake hands. Each businessman shakes the hand of exactly one other businessman. All handshakes happen simultaneously. We say that the shake is perfect if no arms cross each other.

The input will consist of a series of integers n (2 <= n <= 30), terminate by EOF.

N lines, one for each test case in the order they occur in the input file, each containing the string "Case X: Y" where X is the number of the test case, starting from 1, and Y is the number of perfect shakes that exist for n businessmen.