Zipf's Law

Time limit1sMemory limit128 MB

Summary

For each test case, count the words in a book body and print the words that appear exactly n times, in lowercase alphabetical order.

Level: Easy3 of 10
Topics: Hash map, String, Sorting, Implementation
Solved: No attempts yet

Problem

The Harvard linguist George Kingsley Zipf (1902–1950) discovered that, in a given book, the frequency of the $k$ -th most common word is proportional to $1/k$ .

Given the body of an English book, write a program that finds every word that appears exactly $n$ times. A word is a maximal sequence of letters, and words are separated by non-letter characters. Matching is case-insensitive, and every word in the text is a valid English word.

Input

The input consists of several test cases. The first line of each test case contains an integer $n$ . Everything from the next line up to (but not including) the line that reads EndOfText is the body of the book. The body contains at most 10000 words. EndOfText is only a marker that separates test cases and never appears within the body.

Output

For each test case, print every word that appears exactly $n$ times, in alphabetical order, one per line, in lowercase. If there is no such word, print There is no such word.

Print one blank line between consecutive test cases.

Examples4

Example 1

Input

2

In practice, the difference between theory and practice is always
greater than the difference between theory and practice in theory.
	- Anonymous

Man will occasionally stumble over the truth, but most of the
time he will pick himself up and continue on.
        - W. S. L. Churchill
EndOfText
1
the the it it ate ate the Bean bean
EndOfText

Expected output

between
difference
in
will

There is no such word.

Example 2
Input
```
1
hello world
EndOfText
```
Expected output
```
hello
world
```

Example 3

Input

5
a a b
EndOfText

Expected output

There is no such word.

Example 4

Input

2
Cat cat, DOG dog! bird
EndOfText

Expected output

cat
dog