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 Haskell (GHC 8.8.3) (judge verdict: Time Limit Exceeded)

import Data.Char
import Data.List

main = do
  s <- getLine
  print $ compute s

compute :: String -> Int
compute s = sum $ unfoldr step (s,[])
  where
    step ("",_) = Nothing
    step (d:ds,xs) = Just (length $ filter (0 ==) xs', (ds, xs'))
      where
        e = digitToInt d
        f x = (10 * x + e) `mod` 2019
        xs' = e : map f xs