Given an array A of N positive numbers. The task is to find the position where equilibrium first occurs in the array.
Equilibrium position in an array is a position such that the sum of elements below it is equal to the sum of elements after it.
The first line of input contains an integer T denoting the no of test cases then T test cases follow. First line of each test case contains an integer N denoting the size of the array. Then in the next line are N space separated values of the array A.
For each test case in a new line print the position at which the elements are at equilibrium if no equilibrium point exists print -1.
1 <= T <= 100
1 <= N <= 106
1 <= Ai <= 108
1 3 5 2 2
Testcase 1: Since its the only element hence its the only equilibrium point.
Testcase 2: For second test case equilibrium point is at position 3 as elements below it (1+3) = elements after it (2+2).