A14635. Life of a Flower

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:

- If the flower isn't watered for two days in a row, it dies.
- If the flower is watered in the $i$ -th day, it grows by $1$ centimeter.
- If the flower is watered in the $i$ -th and in the $(i-1)$ -th day ( $i > 1$ ), then it grows by $5$ centimeters instead of $1$ .
- If the flower is not watered in the $i$ -th day, it does not grow.

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.