# Two-digit numbers 3

Execution time limit is 1 second

Runtime memory usage limit is 64 megabytes

Calculate the sum of all two-digit numbers where the digits are in descending order and their sum equals m.

## Input

A natural number m, where 0 ≤ m ≤ 20.

## Output

A single integer representing the solution to the problem.

## Examples

Input #1

Answer #1

Input #2

Answer #2

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Acceptance rate 59%