The sum of products of digits#8683

The sum of products of digits

1 second

128 megabytes

Very easy

Find the sum of products of all digits for $k$ -digit numbers.

For example, for $k = 2$ k = 2 the two-digit numbers are $10$ , $11$ , $12$ , $\dots$ , $98$ , $99$ . The sum of products of their digits is $1 \cdot 0 + 1 \cdot 1 + 1 \cdot 2 + \dots + 9 \cdot 8 + 9 \cdot 9 = 2025$ 1 \cdot 0 + 1 \cdot 1 + 1 \cdot 2 + \ldots + 9 \cdot 8 + 9 \cdot 9 = 2025.

Input

One positive integer $k$ ( $k \leq 10$ k \leq 10).

Output

Print the sum of products of all digits for $k$ -digit numbers.

Examples

Example 1

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k = 2

1 \cdot 0 + 1 \cdot 1 + 1 \cdot 2 + \dots + 9 \cdot 8 + 9 \cdot 9 = 2025

k \leq 10