

Series 1Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 2173 Accepted Submission(s): 689 Problem Description Let A be an integral series {A_{1}, A_{2}, . . . , A_{n}}. The zeroorder series of A is A itself. The firstorder series of A is {B_{1}, B_{2}, . . . , B_{n1}},where B_{i} = A_{i+1}  A_{i}. The ithorder series of A is the firstorder series of its (i  1)thorder series (2<=i<=n  1). Obviously, the (n  1)thorder series of A is a single integer. Given A, figure out that integer. Input The input consists of several test cases. The first line of input gives the number of test cases T (T<=10). For each test case: The first line contains a single integer n(1<=n<=3000), which denotes the length of series A. The second line consists of n integers, describing A_{1}, A_{2}, . . . , A_{n}. (0<=A_{i}<=10^{5}) Output For each test case, output the required integer in a line. Sample Input
Sample Output
Author BUPT Source  
