Unique Substrings Generation

Given an integer \(n\) with \(1 \le n \le 26\), generate a string of length \(n\) such that every substring of length \(k\) (for all \(1 \leq k \leq n\)) is unique. In other words, the string must be constructed in such a way that no two substrings of the same length are identical.

The string should consist only of lowercase English letters (a to z). A simple observation is that the first \(n\) letters of the English alphabet naturally satisfy the condition. For example:

• For \(n = 1\), the output is a.
• For \(n = 3\), the output is abc.
• For \(n = 5\), the output is abcde.

Your task is to implement a program that reads an integer from standard input and outputs the corresponding string to standard output.

inputFormat

The input consists of a single integer \(n\) representing the length of the string. It is given via standard input.

Constraints:

• \(1 \le n \le 26\)

outputFormat

Output a string of length \(n\) that satisfies the property that every substring of length \(k\) (for \(1 \leq k \leq n\)) is unique. The output should be written to standard output.

1

a