CF1606C Banknotes

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.