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 Go (1.14.1) (judge verdict: Wrong Answer)

package main

import (
	"fmt"
)

func countMod(str string) map[int]int {
	const div = 2019
	prev := 0
	l := len(str)
	digit := 1
	count := make(map[int]int)
	count[0] = 1
	for i := l - 1; i >= 0; i-- {
		n := int(rune(str[i]) - '0')
		mod := (n*digit + prev) % div
		count[mod]++
		prev = mod
		digit *= 10
	}
	return count
}

func solve(str string) int {
	count := countMod(str)
	ans := 0
	for _, v := range count {
		ans += v * (v - 1) / 2
	}
	return ans
}

func main() {
	var str string
	fmt.Scan(&str)

	ans := solve(str)
	fmt.Println(ans)
}