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
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        long ans = 0;
        for (int i=0;i<10;i++){
            for (int j=0;j<10;j++){
                int cij = 0;
                int cji = 0;
                for (int k=1;k<=n;k++){
                    String s = Integer.toString(k);
                    if (s.charAt(0)-'0'==i&&k%10==j)cij++;
                    if (s.charAt(0)-'0'==j&&k%10==i)cji++;
                }
                ans+=cij*(long)cji;
            }
        }
        System.out.println(ans);
    }
}
