#799. Two 20-sided dice
You roll two 20-sided dice (1-20). In how many ways can the sum be s? (The order matters.)
### Input
One integer s.
### Output
A number.
Examples
Input
13
Output
12
Input
31
Output
10
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.