A sequence is an arithmetic sequence if every two successive numbers have the same difference. Suppose this is a sequence of numbers:

a₁, a₂, a₃, ... a_n

This is an arithmetic sequence if a_i - a_i+1 is the same for each i from 1 to n-1.

You are given first 3 terms of a sequence and the value of n. If it is an arithmetic sequence you must print the nth term. Otherwise you must print “Error”.

Input

In first line there will an integer T denoting the number of test cases. Each of the next 3 lines will contain 4 integers a₁, a₂, a₃ and n.

Output Format

In each line specify the case number and print the answer.

Constraints

-300 <= a₁, a₂, a₃ <= 300

1 <= n <= 1000

Example

Input:
3
1 2 3 10
1 4 3 10
15 30 45 5

Output:
Case 1: 10
Case 2: Error
Case 3: 75

Problem-setter: Shafaet Ashraf