Scared String!

You need to construct a string $s$ of length $n$ consisting of lowercase English letters (from "a" to "z") that is not scared.

Let a string $s$ be scared if there is at least one character in the string that sees more than $20$ characters that are greater than or equal to it.

We define a character $a$ to be greater than character $b$ if character $a$ comes after character $b$ in the alphabet. For example, "f" $>$ "b". Also, if character $a$ is greater than character $b$, then we define $b$ to be smaller than $a$ (for example, "b" $<$ "f").

We say that the character at position $i$ sees the character at position $j$ if $j<i$ and there is no index $k$ $(j<k<i)$ such that $s_k$ is greater than $s_j$.

For example, in the string "abacc", the "a" at position $3$ does not see the "a" at position $1$ because between them there is "b" which is greater than the "a" at position $1$. But the "c" at position $4$ can see the "b" at position $2$ because between them the greatest character is "a" which is not greater than the "b" at position $2$.

Input

The only line contains a single integer $n$ $(1\le n\le 10^5)$ — the size of the string which you need to construct.

Output

In the only line, you need to output the string of length $n$ which is not scared and consists only of lowercase English letters.

Examples

Note

In the first test case, the string "anton" is not scared because no character sees more than $20$ characters that are greater than or equal to it:

• the first character "a" does not see anything;

• the second character "n" sees only "a" but it is smaller than "n";

• the third character "t" sees "n", but it is smaller than "t";

• the fourth character "o" sees only "t";

• the fifth character "n" sees "t" and "o" that are greater than $s_5=$ "n", but there are only $2$ such characters, which is less than $20$.

Also, notice that in the third test case, in the string "aabbaa", the $6$-th character "a" sees both "b"'s at the $3$-rd and at the $4$-th positions since there are no characters between the $3$-rd and the $6$-th ones which are greater than "b".

Scoring

1. ($52$ points): $n\le 400$;

2. ($86$ points): $n\le 8000$;

3. ($162$ points): no additional constraints.