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 number 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).