# Day 1 Problem 2

## Common Words

Source file: words.c or words.cpp or words.pas
Input file: words.in
Output file: words.out

Given a sequence of m words from a newspaper article and an integer k, find the kth most common word.

### Input Specification

Input will consist of an integer n followed by n data sets. Each data set begins with a line containing m and k, followed by m lines, each containing a word of up to 20 lower case letters. There will be no more than 1000 words per data set.

### Output Specification

For each input data set, determine the kth most common word(s). To be precise, a word w is the kth most common if exactly k-1 distinct words occur more frequently than w in the data set. Note that w might be multiply defined (i.e. there is a tie for the kth most common word) or w might not exist (i.e. there is no kth most common word). For each data set, print a title line indicating k using normal ordinal notation (1st, 2nd, 3rd, 4th, 5th, ...) followed by a number of lines giving all the possible values for the kth most common word. A blank line should follow the last word for each data set.

```3
7 2
the
brown
the
fox
red
the
red
1 3
the
2 1
the
wash
```

### Output for Sample Input

```2nd most common word(s):
red

3rd most common word(s):

1st most common word(s):
the
wash
```