CF1702D Not a Cheap String

Let $ s $ be a string of lowercase Latin letters. Its price is the sum of the indices of letters (an integer between 1 and 26) that are included in it. For example, the price of the string abca is $ 1+2+3+1=7 $ . The string $ w $ and the integer $ p $ are given. Remove the minimal number of letters from $ w $ so that its price becomes less than or equal to $ p $ and print the resulting string. Note that the resulting string may be empty. You can delete arbitrary letters, they do not have to go in a row. If the price of a given string $ w $ is less than or equal to $ p $ , then nothing needs to be deleted and $ w $ must be output. Note that when you delete a letter from $ w $ , the order of the remaining letters is preserved. For example, if you delete the letter e from the string test, you get tst.

The first line of input contains an integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases in the test. The following are descriptions of $ t $ test cases. Each case consists of two lines. The first of them is the string $ w $ , it is non-empty and consists of lowercase Latin letters. Its length does not exceed $ 2\cdot10^5 $ . The second line contains an integer $ p $ ( $ 1 \le p \le 5\,200\,000 $ ). It is guaranteed that the sum of string lengths $ w $ over all test cases does not exceed $ 2 \cdot 10^5 $ .

Output exactly $ t $ rows, the $ i $ -th of them should contain the answer to the $ i $ -th set of input data. Print the longest string that is obtained from $ w $ by deleting letters such that its price is less or equal to $ p $ . If there are several answers, then output any of them. Note that the empty string — is one of the possible answers. In this case, just output an empty string.