Problem:
Score : 400 points

Problem Statement

Given is a string S consisting of digits from 1 through 9.

Find the number of pairs of integers (i,j) (1 ≤ i ≤ j ≤ |S|) that satisfy the following condition:

Condition: In base ten, the i-th through j-th characters of S form an integer that is a multiple of 2019.

Constraints

1 ≤ |S| ≤ 200000

S is a string consisting of digits from 1 through 9.

Input

Input is given from Standard Input in the following format:

S

Output

Print the number of pairs of integers (i,j) (1 ≤ i ≤ j ≤ |S|) that satisfy the condition.

Sample Input 1

1817181712114

Sample Output 1

3

Three pairs - (1,5), (5,9), and (9,13) - satisfy the condition.

Sample Input 2

14282668646

Sample Output 2

2

Sample Input 3

2119

Sample Output 3

0

No pairs satisfy the condition.

Solution in Julia (1.4.0) (judge verdict: Accepted)

using DataStructures
MOD = 2019

function main()
  a = readline() |> s -> split(s,"") |> xs -> parse.(Int,xs) |> reverse
  n = length(a)
  dp = zeros(Int, n+1)

  for i in 1:n
    dp[i+1] = (powermod(10, i-1, MOD) * a[i] + dp[i]) % MOD
  end

  cnt = counter(Int)
  for x in dp
    inc!(cnt, x)
  end
  ans = [x * (x-1) ÷ 2 for (k,x) in cnt] |> sum

  println(ans)
end

main()