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 Ruby (2.7.1) (judge verdict: Accepted)

S = gets.chomp.split("").map &:to_i
N = S.size
Mod = 2019
a = 0
q = 1
A = S.reverse!.map{ |s|
  a = (a + s * q) % Mod
  q = q * 10 % Mod
  a
}
A.reverse!
A << 0
cnt = Array.new(2019, 0)
ans = 0
(0...A.size-1).reverse_each{ |i|
  a = A[i]
  b = A[i+1]
  ans += cnt[a]
  cnt[b] += 1
}
p ans