Problems
Constant sum of digits
Constant sum of digits
Find the amount of two-digit numbers that do not change their sum of digits when multiplying a number by a single-digit integer n (n = 0 .. 9).
Input data
One integer n (0 ≤ n ≤ 9).
Output data
Print the required amount of two-digit numbers.
Examples
Input example #1
2
Output example #1
10