Problem:
Score : 200 points

Problem Statement

Find the sum of the integers between 1 and N (inclusive), whose sum of digits written in base 10 is between A and B (inclusive).

Constraints

1 \leq N \leq 10^4

1 \leq A \leq B \leq 36

All input values are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

Print the sum of the integers between 1 and N (inclusive), whose sum of digits written in base 10 is between A and B (inclusive).

Sample Input 1

20 2 5

Sample Output 1

84

Among the integers not greater than 20, the ones whose sums of digits are between 2 and 5, are: 2,3,4,5,11,12,13,14 and 20. We should print the sum of these, 84.

Sample Input 2

10 1 2

Sample Output 2

13

Sample Input 3

100 4 16

Sample Output 3

4554

Solution in Ruby (2.3.3) (judge verdict: Accepted)

n, a, b = STDIN.gets.chomp.split.map{|s| s.to_i }

total = 0
(1..n).each do |i|
  str_i   = i.to_s
  i_10000 = str_i[-5].to_i
  i_1000  = str_i[-4].to_i
  i_100   = str_i[-3].to_i
  i_10    = str_i[-2].to_i
  i_1     = str_i[-1].to_i
  sum = i_10000 + i_1000 + i_100 + i_10 + i_1
  if (a <= sum) && (sum <= b)
    total += i
  end
end

puts total