Problem:
Score : 200 points

Problem Statement

Find the number of palindromic numbers among the integers between A and B (inclusive).
Here, a palindromic number is a positive integer whose string representation in base 10 (without leading zeros) reads the same forward and backward.

Constraints

10000 \leq A \leq B \leq 99999

All input values are integers.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the number of palindromic numbers among the integers between A and B (inclusive).

Sample Input 1

11009 11332

Sample Output 1

4

There are four integers that satisfy the conditions: 11011, 11111, 11211 and 11311.

Sample Input 2

31415 92653

Sample Output 2

612

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System.Linq;
using System;
using System.IO;

class Program
{
  static void Main(string[] args) =>
    new Program().solve();

  private void solve()
  {
    var seq = Console.ReadLine().Split(' ')
      .Select(int.Parse).ToArray();
    var a = seq[0];
    var b = seq[1];
    
    var ans = Enumerable.Range(a, b - a + 1)
      .Aggregate(0, (acc, i) =>
        i == reverse(acc:0, n:i) ? acc + 1 : acc);

    Console.WriteLine(ans);
  }

  private int reverse(int acc, int n)
  {
    if(n == 0) return acc;
    else return reverse(acc * 10 + (n % 10), n / 10);
  }
}