You are given an array \(A\) of \(N\) integers. Find the smallest index \(i\) \((1 \le i \le N - 1)\) such that:

• \(mex(A[1], A[2], .. , A[i]) = mex(A[i+1], A[i+2],... , A[N])\)

If no such index exists, print \(-1\).

Input format

• The first line contains an integer \(T\) denoting the number of test cases.
• For each test case:-
• The first line of each test case contains an integer \(N\) denoting the number of elements in array \(A\).
• The second line contains \(N\) space-separated integers denoting the elements of the array.

Output format

For each test case in a new line, print the smallest index satisfying the condition.

Constraints

\(1 \le T \le 10 \\ 1 \le N \le 10^5 \\ 0 \le A[i] \le 10^5 \\ \)

Note

• 1-based Indexing is followed.
• \(mex\) of an array of elements is defined as the minimum non-negative number missing from the array.