A stem-and-leaf display is a device for presenting quantitative data in a graphical format, similar to a histogram, to assist in visualizing the shape of a distribution.

Example

Given some series of numbers like this

 12 15 14 23 24 26 28 33 38 39

you should convert it this one

 1 | 245
 2 | 3468
 3 | 389

 input is  {'12','15','14','23','24','26','28','33','38','39'}

 output will be {'1245','23468','3389'}

Note: input numbers must be sorted increasing order.