Life of a Flower

题意翻译

有一朵花，原高度为 $1$，现在有 $n$ 天去种植它。 对于第 $i$ 天 - 如果第 $i$ 和 $i-1$ 天都没有浇水，这朵花会挂掉。 - 如果第 $i-1$ 天没有浇水，第 $i$ 天浇水了，这一天这朵花会长高 $1$。 - 如果第 $i-1$ 和 $i$ 天都浇水了，这一天会长高 $5$。 求最后花的高度，如果挂掉了，输出 $-1$。

题目描述

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?

输入输出格式

输入格式

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.

输出格式

For each test case print a single integer $ k $ — the flower's height after $ n $ days, or $ -1 $ , if the flower dies.

输入输出样例

输入样例 #1

4
3
1 0 1
3
0 1 1
4
1 0 0 1
1
0

输出样例 #1

3
7
-1
1