There are two singly linked lists in a system. By some programming error the end node of one of the linked list got linked into the second list, forming a inverted Y shaped list. Write a program to get the point where two linked lists merge.

Above diagram shows an example with two linked list having 15 as intersection point.
Expected time complexity is O(m + n) where m and n are lengths of two linked lists

Input:
You have to complete the method which takes two arguments as heads of two linked lists. 

Output:
The function should return data value of a node where two linked lists merge.  If linked list do not merge at any point, then it shoudl return -1.

Constraints:
1 <=T<= 50
1 <=N<= 100
1 <=value<= 1000

Example:
Input:
2
2 3 2
10 20
30 40 50
5 10
2 3 0
10 20
30 40 50
First line is number of test cases. Every test case has four lines. First line of every test case contains three numbers, x (number of nodes before merge point in 1st list), y(number of nodes before merge point in 11nd list) and z (number of nodes after merge point).  Next three lines contain x, y and z values.

Output:
5
-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, and should not print anything on stdout/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 **