Challenges

Bitwise for Dummies
This is to provide you with an introductory experience of bit-wise ope...
Max. Marks: 6
Solved By : 109
Double the Number
Given an array A of size N and K. count all the number of elements suc...
Max. Marks: 8
Solved By : 187
Rotate Array
You are given an array of N length. You have to rotate the array right...
Max. Marks: 6
Solved By : 1579
Floating Number
Bob has a floating point number N. He wants to set the precision for 2...
Max. Marks: 4
Solved By : 5066
SwapMaster solves Symmetric Swap
The SwapMaster is known to be the greatest and fastest swapper of all ...
Max. Marks: 4
Solved By : 4187
String Matching
Cody has a sequence of characters N. He likes a sequence if it contain...
Max. Marks: 3
Solved By : 2347
Leap Year
Steve is playing a quiz game with his brother John. As Steve just lear...
Max. Marks: 6
Solved By : 3622
Project Teams
There are N students in a class and Teacher want to divide these stude...
Max. Marks: 5
Solved By : 4319
Circle of Numbers
All numbers in NumberLand are standing in a circle for a dancing cerem...
Max. Marks: 6
Solved By : 2978
Happy String
A happy string is a string in which each character is lexicographicall...
Max. Marks: 4
Solved By : 2235
Arithmetic Sequence
Please select a challenge
Problem Statement
In mathematics, an arithmetic progression (AP) or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. John was writing an Arithmetic sequence with N terms, but while writing he mistakenly made one wrong entry and he is sure that first term is right. Help him to find the wrong term entered by him.

Input
The first line of input contains a single line T, which represents the number of testcases. Then first line of each test case contains an integer N :Total number of terms. Then N space separated integers denoting the sequence.

Output
For each test case. Print the wrongly entered term.

Constraints
1<=T<=100. 4<=N<=1000. 1<=Terms<=1000.

Sample Input
2
5
1 3 5 6 9
4
1 2 3 5

Sample Output

6
5

Dcoded By: Bhanu Nadar

Solved By: 546

Maximum Marks: 6