Preparando MOJI
Petya has got an interesting flower. Petya is a busy person, so he sometimes forgets to water it. You are given $$$n$$$ 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 $$$1$$$-st day the flower is $$$1$$$ centimeter tall. What is its height after $$$n$$$ days?
Each test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 100$$$). Description of the test cases follows.
The first line of each test case contains the only integer $$$n$$$ ($$$1 \leq n \leq 100$$$).
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \dots, a_n$$$ ($$$a_i = 0$$$ or $$$a_i = 1$$$). If $$$a_i = 1$$$, the flower is watered in the $$$i$$$-th day, otherwise it is not watered.
For each test case print a single integer $$$k$$$ — the flower's height after $$$n$$$ days, or $$$-1$$$, if the flower dies.
4 3 1 0 1 3 0 1 1 4 1 0 0 1 1 0
3 7 -1 1