Problem G
Time Limit: 1 second
Memory Limit: 1000K

Let us denote the sum of digits of the number N by S(N). In this problem, we want you to determine, how often the following equality holds:
S(A+B) = S(A) + S(B)

Input

The input file contains a single positive integer K, 0 < K <= 50.

Output

You should output the number of pairs of Ê-digit numbers A and B to satisfy the above equality. Counting that number you should be aware of the following:
  1. Numbers A and B should not have leading zeroes
  2. While counting the total number of pairs, the order of numbers A and B matters, thus, for instance, (12, 26) and (26, 12) are different pairs that satisfy the conditions of the problem.

Sample Input

2

Sample Output

1980