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.