Given is a positive integer N.

Find the number of pairs (A, B) of positive integers not greater than N that satisfy the following condition:
- When A and B are written in base ten without leading zeros, the last digit of A is equal to the first digit of B, and the first digit of A is equal to the last digit of B.

-----Constraints-----
- $1 \leq N \leq 2 \times 10^5$
- All values in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
N

-----Output-----
Print the answer.

-----Sample Input-----
25

-----Sample Output-----
17

The following 17 pairs satisfy the condition: (1,1), (1,11), (2,2), (2,22), (3,3), (4,4), (5,5), (6,6), (7,7), (8,8), (9,9), (11,1), (11,11), (12,21), (21,12), (22,2), and (22,22).

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