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.

Examples

Input

25

Output

17

Input

1

Output

1

Input

100

Output

108

Input

2020

Output

40812

Input

200000

Output

400000008

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见题面