BETA

The Celebrity Problem
##### Submissions: 10036   Accuracy: 35.08%   Difficulty: Easy

You are in a party of N people, where only one person is known to everyone. Such a person may be present in the party, if yes, (s)he doesn’t know anyone in the party. Your task is to find the stranger (celebrity) in party.
You will be given a square matrix M where if an element of row i and column j  is set to 1 it means there is an edge from ith person to jth person. An edge represent the relation that i th person knows j th person. You need to complete the function getId which finds the id of the celebrity if present else return -1. The function getId takes two arguments the square matrix M and its size n.

Input:
The first line of input contains an element T denoting the No of test cases. Then T test cases follow. Each test case consist of 2 lines. The first line of each test case contains a number denoting the size of the matrix M. Then in the next line are space separated values of the matrix M.

Output:
For each test case output will be the id of the celebrity if present (0 based index). Else -1 will be printed.

Constraints:
1<=T<=60
2<=N<=40
0<=M[][]<=1

Example:
Input (To be used only for expected output)

1
3
0 1 0 0 0 0 0 1 0

Output
1

Explanation
For the above test case the matrix will look like
0 1 0
0 0 0
0 1 0

Here  the celebrity is the person with index 1 ie id 1

Note:The Input/Ouput format and Example given are used for system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from stdin/console. The task is to complete the function specified, and not to write the full code.

#### ** For More Input/Output Examples Use 'Expected Output' option **

Contributor: Amit Khandelwal, Harshit Sidhwa
Author: Shubham Joshi 1