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)

def sum(n)
    a = 0
    a += n / 10000
    n %= 10000
    a += n / 1000
    n %= 1000
    a += n / 100
    n %= 100
    a += n / 10
    n %= 10
    a += n
    return a
end

num = gets.chomp.split(" ").map(&:to_i)
ans = 0
for i in 1..num[0] do
    sumsum = sum(i)
    if (num[1] <= sumsum) && (sumsum <= num[2])
        ans += i
    end
end
puts ans