Problem:
Score : 400 points

Problem Statement

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 1

25

Sample Output 1

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).

Sample Input 2

1

Sample Output 2

1

Sample Input 3

100

Sample Output 3

108

Sample Input 4

2020

Sample Output 4

40812

Sample Input 5

200000

Sample Output 5

400000008

Solution in JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

process.stdin.resume();
process.stdin.setEncoding('utf8');
 
var lines = [];
var reader = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
});
reader.on('line', (line) => {
    // ここで入力を処理する
    lines.push(line);
});
var sub_fn = (ary)=>{
  
}
reader.on('close', () => {
  var x = 1*lines[0].split(' ')[0]
  var y = lines[0].split('')
  //console.log(x)
  var cnt = 0;
  for(var i=1;i<=x;i++){
    var ii = ("" + i).split('');
    //console.log(ary)
   // console.log(ary[0] == ary[ary.length - 1])
    
      for(var j=1;j<=x;j++){
    var jj = ("" + j).split('');
          if(ii[0] == jj[jj.length - 1] && ii[ii.length - 1] == jj[0]){
      ++cnt
      }

    }
  }
  console.log(cnt)



  
});