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 Ruby (2.3.3) (judge verdict: Accepted)

# A  以上 B 以下の整数のうち、回文数となるものの個数を求めてください。
# ただし、回文数とは、先頭に 0 をつけない 10 進表記を文字列として見たとき、
# 前から読んでも後ろから読んでも同じ文字列となるような正の整数のことを指します。

input = gets.chomp.split
a = input[0].to_i
b = input[1].to_i

count = 0
i = a
while i <= b
  i = i.to_s

  if i == i.reverse
    count += 1
  end

  i = i.to_i
  i += 1
end

puts count