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"
	"strconv"
)

var S string

func main() {
	fmt.Scan(&S)
	a := make([]int, len(S))
	for i, v := range S {
		a[i], _ = strconv.Atoi(string(v))
	}
	b := map[int]int{
		len(S): 0,
	}
	c := 1
	d := map[int]bool{
		0: true,
	}
	res := 0
	for i := len(S) - 1; i >= 0; i-- {
		b[i] = (a[i]*c + b[i+1]) % 2019
		c *= 10
		if d[b[i]] {
			res++
			continue
		}
		d[b[i]] = true
	}

	fmt.Printf("%d",res)
}