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 OCaml (4.02.3) (judge verdict: Accepted)

let rec sum_of_digits x res =
  if x = 0 then res else
  sum_of_digits (x/10) (res+x mod 10)

let solve n a b =
  let rec count m res =
    if m > n then res else
    let s = sum_of_digits m 0 in
    count (m+1) (res + if a <= s && s <= b then m else 0)
  in
  count 1 0

let () =
  Scanf.scanf "%d %d %d\n" @@ fun n a b -> 
  Printf.printf "%d\n" @@ solve n a b