Petya has got an interesting flower. Petya is a busy person, so he sometimes forgets to water it. You are given nn days from Petya's live and you have to determine what happened with his flower in the end.
The flower grows as follows:
At the beginning of the 11-st day the flower is 11 centimeter tall. What is its height after nn days?
Each test contains multiple test cases. The first line contains the number of test cases tt (1≤t≤1001≤t≤100). Desc
The first line of each test case contains the only integer nn (1≤n≤1001≤n≤100).
The second line of each test case contains nn integers a1,a2,…,ana1,a2,…,an (ai=0ai=0 or ai=1ai=1). If ai=1ai=1, the flower is watered in the ii-th day, otherwise it is not watered.
For each test case print a single integer kk — the flower's height after nn days, or −1−1, if the flower dies.
4
3
1 0 1
3
0 1 1
4
1 0 0 1
1
0
3
7
-1
1