Merge the Tools

You are given a string s and an integer k. Your task is to split the string s into substrings of size k (the last substring may be shorter than k if s's length is not a multiple of k). For each substring, remove any duplicate characters while maintaining the order of their first occurrence. Print each resulting substring on a new line.

Note:

• If the character appears multiple times in the substring, only its first occurrence should be kept.

Example:

Input: s = "AABCAAADA", k = 3
Output:
AB
CA
AD
Input: s = "AAABBBCCC", k = 3
Output:
A
B
C

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inputFormat

The input is read from standard input (stdin) and consists of two lines:

• The first line contains a non-empty string s, comprising uppercase letters.
• The second line contains an integer k, representing the length of each substring to process.

outputFormat

The output should be written to standard output (stdout). For each substring of length k (or the last substring which might be shorter), print the substring after removing duplicate characters, each on a new line.

## sample

AABCAAADA
3

AB
CA
AD

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