Given a positive integer $n$, count the number of sets of positive integers $x_1 < x_2 < x_3 < x_4$ such that:
$$x_1+x_2+x_3+x_4=n$$
### Input
- A single line containing a positive integer $n$.
### Output
- Print an integer representing the number of sets.
### Constraints
- $1 \le n \le 50$.
### Example
Input:
```
10
```
Output:
```
1
```
