Problem

Consider the following:

• A string,s , of length n where s = cc1 ....... .
• An integer, k, where k is a factor of n.

We can split  into  substrings where each subtring, , consists of a contiguous block of  characters in . Then, use each  to create string  such that:

The characters in  are a subsequence of the characters in .

Any repeat occurrence of a character is removed from the string such that each character in  occurs exactly once. In other words, if the character at some index  in  occurs at a previous index  in , then do not include the character in string .

Given  and , print  lines where each line  denotes string .

---

Example

There are three substrings of length  to consider: 'AAA', 'BCA' and 'DDE'. The first substring is all 'A' characters, so . The second substring has all distinct characters, so . The third substring has  different characters, so . Note that a subsequence maintains the original order of characters encountered. The order of characters in each subsequence shown is important.

---

Function Description

Complete the merge_the_tools function in the editor below.

merge_the_tools has the following parameters:

string s: the string to analyze

int k: the size of substrings to analyze

---

Prints

Print each subsequence on a new line. There will be  of them. No return value is expected.

---

Input Format

The first line contains a single string, .

The second line contains an integer, , the length of each substring.

---

Sample Input

STDIN       Function
-----       --------
AABCAAADA   s = 'AABCAAADA'
3           k = 3

---

Sample Output

AB
CA
AD

---

Explanation

Split  into  equal parts of length . Convert each  to  by removing any subsequent occurrences of non-distinct characters in :

Print each  on a new line. 

---

Solution

1
2
3
4
5
6
7
8
9

from collections import OrderedDict
def merge_the_tools(string, k):
    strlen = len(string)
    for i in range(0,strlen,k):
        print(''.join(OrderedDict.fromkeys(string[i:i + k])))
        
if __name__ == '__main__':
    string, k = input(), int(input())
    merge_the_tools(string, k)