\problemname{Lyrical Leisure}

\illustration{0.3}{limage.png}{
    Ornament from a 1923 magazine.
    Public domain on \href{https://commons.wikimedia.org/wiki/File:Books_and_Scroll_Ornament_with_Open_Book.png}{Wikimedia Commons} by an anonymous author.
}

% optionally define variables/limits for this problem
\newcommand{\maxn}{5000}
\newcommand{\person}{Hannah}

\person's favourite leisure activity is to write poems. She particularly likes
to write about the small things in everyday life and about neat patterns. For
example, she enjoys to write poems utilizing palindromes, since her name is also
one! A palindrome is a string which is equal to its reverse, ignoring the letter
cases.

However, she would like to introduce a small twist. In the grocery store, she
was in the fruit section. When she was about to take a banana, she realized the
word consists of the letter `\texttt{b}', followed by the palindrome
`\texttt{anana}' of length 5. Her whole life, she has played around with
palindromes, but never with words containing them. 

At home, she immediately started to think of interesting words containing
palindromes. Given two lengths $n$ and $k$, she would like to find a method that
constructs a string of length $n$, whose longest palindromic substring is of
length $k$. A substring of a string $s$ is a sequence of consecutive characters
of $s$.

For now, she does not care about whether the string this method provides is an
actual word in the dictionary, and any string will suffice.

\begin{Input}
    The input consists of:
    \begin{itemize}
        \item One line with two integers $n$ and $k$ ($1\leq k\leq n\leq \maxn$), the
            length of the string and the length of the longest palindromic
            substring.
    \end{itemize}
\end{Input}

\begin{Output}
    Output a string of length $n$ consisting of English letters
    (\texttt{a}-\texttt{z} and \texttt{A}-\texttt{Z}) whose longest palindromic
    substring is of length $k$.

    If there are multiple valid solutions, you may output any one of them.
\end{Output}