p02792 AtCoder Beginner Contest 152 - Handstand 2
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
```python
N = int(input())

l = [[0 for j in range(10)] for i in range(10)]

for n in range(1, N+1):
  s = str(n)
  i = int(s[0])
  j = int(s[-1])
  l[i][j] += 1

ans = sum([l[i][j]*l[j][i] for i in range(10) for j in range(10)])

print(ans)
```