# Count Of Valleys And Mountains

easy

1. You are given a number n, representing the number of upstrokes / and number of downstrokes . 2. You are required to find the number of valleys and mountains you can create using strokes. E.g. Note -> At no point should we go below the sea-level. (number of downstrokes should never be more than number of upstrokes).

## Constraints

0 <= n <= 15

## Format

### Input

A number n

### Output

A number representing the number of valleys and mountains you can create using strokes.

## Example

Sample Input

4

### Sample Output

14

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