Banknotes

### 题意简述 有 $n$ 中面额的钞票，第 $i$ 种钞票面额为 $10^{a_i}$ 勃朗。（保证 $a_1=0$） 定义 $f(s)$ 为组成 $s$ 勃朗最少需要多少张钞票。 给定 $k$，问使得 $f(s)>k$ 的最小 $s$ 是多少。 ### 输入格式 多组数据。第一行一个整数 $T\ (1\le T\le 10^4)$。 对于每组数据，第一行是两个整数 $n,k\ (1\le n\le 10,\ 1\le k\le 10^9)$。 接下来一行有 $n$ 个整数 $a_1,\ a_2,\ \dots,\ a_n\ (0=a_1<a_2<\dots <a_n\le 9)$。 ### 输出格式 对于每组数据，输出一个整数表示答案。

In Berland, $ n $ different types of banknotes are used. Banknotes of the $ i $ -th type have denomination $ 10^{a_i} $ burles (burles are the currency used in Berland); the denomination of banknotes of the first type is exactly $ 1 $ . Let's denote $ f(s) $ as the minimum number of banknotes required to represent exactly $ s $ burles. For example, if the denominations of banknotes used in Berland are $ 1 $ , $ 10 $ and $ 100 $ , then $ f(59) = 14 $ : $ 9 $ banknotes with denomination of $ 1 $ burle and $ 5 $ banknotes with denomination of $ 10 $ burles can be used to represent exactly $ 9 \cdot 1 + 5 \cdot 10 = 59 $ burles, and there's no way to do it with fewer banknotes. For a given integer $ k $ , find the minimum positive number of burles $ s $ that cannot be represented with $ k $ or fewer banknotes (that is, $ f(s) > k $ ).

The first line contains a single integer $ t $ ( $ 1 \le t \le 10^4 $ ) — number of test cases. The first line of each test case contains two integers $ n $ and $ k $ ( $ 1 \le n \le 10; 1 \le k \le 10^9 $ ). The next line contains $ n $ integers $ a_1, a_2, \dots, a_n $ ( $ 0 = a_1 < a_2 < \dots < a_n \le 9 $ ).

For each test case, print one integer — the minimum positive number of burles $ s $ that cannot be represented with $ k $ or fewer banknotes.

4
3 13
0 1 2
2 777
0 4
3 255
0 1 3
10 1000000000
0 1 2 3 4 5 6 7 8 9

59
778
148999
999999920999999999