| David is labelling boxes in a giant warehouse. He has a *lot* of boxes to | |
| label, but unfortunately his labeling machine is broken, so only some of the | |
| letters work. In order to be efficient, David labels the boxes by first using | |
| every possible 1-letter label in alphabetical order, then using every possible | |
| 2-letter label in alphabetical order, then every 3-letter label, etc. | |
| For example, suppose only the letters 'D', 'T', and 'Z' work. David would | |
| label the first 15 boxes as follows: D, T, Z, DD, DT, DZ, TD, TT, TZ, ZD, ZT, | |
| ZZ, DDD, DDT, DDZ. The first box is considered box #1, not box #0. | |
| Given a set of working letters **L** on David's labelling machine and a number | |
| **N** of boxes to label, return the label on the last box. | |
| ## Input | |
| The first line of the input consists of a single integer **T**, the number of | |
| test cases. | |
| Each test case consists of the string **L** and the integer **N**, separated | |
| by a space. | |
| ## Output | |
| For each test case **i** numbered from 1 to **T**, output "Case #**i**: ", | |
| followed by the label on the last box. | |
| ## Constraints | |
| 1 ≤ **T** ≤ 20 | |
| 1 ≤ length(**L**) ≤ 25 | |
| **L** will be in alphabetical order, consist of only uppercase letters A-Z, and contain each letter at most once | |
| 1 ≤ **N** ≤ 263-1 | |
| The test cases will be designed so that no label is longer than 50 letters | |