Interesting Number#4965

Interesting Number

1 second

128 megabytes

Very easy

Tyomitch calls the number with $2 n$ digits (without leading zeroes) "interesting", if it's divisible by both the number formed from its first $n$ digits and the number formed from its last $n$ digits. For example, $1020$ is "interesting" (divisible by $10$ and $20$ ) and $2005$ is not. Tyomitch wants to know how many "interesting" $2 n$ -digit numbers exist. You are to help him.

Input

One integer $n$ ( $1$ ≤ $n$ ≤ $10000$ ).

Output

Print the number of "interesting" $2 n$ -digit numbers.

Examples

Example 1

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