# Number Of Paths Along The Edges In Upper Half Of A Square Matrix

easy

1. You are given a number N, which represents the size of a square matrix. 2. You have to find the total number of paths along the edges in the given square matrix. 3. You are allowed to travel only in the upper half of the matrix(i.e you can't cross the middle diagonal of the matrix).

## Constraints

1 <= N <= 15

## Format

### Input

A number N

### Output

A number representing total number paths along the edges in upper half of given square matrix.

## Example

Sample Input

3

### Sample Output

5