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: Time Limit Exceeded)

package main

import (
	"fmt"
	"strconv"
)

func main() {
	var s string
	fmt.Scanf("%s", &s)
	answer := countPairs(s)
	fmt.Println(answer)
}

func countPairs(s string) int {
	if len(s) < 5 {
		return 0
	}
	count := 0
	countMap := make(map[string]int)
	for i := 0; i < len(s)-4; i++ {
		for j := i + 5; j <= len(s); j++ {
			rawStr := s[i:j]
			if countMap[rawStr] != 0 {
				count += countMap[rawStr]
			} else {
				num, _ := strconv.Atoi(rawStr)
				if num%2019 == 0 {
					count++
					countMap[rawStr] = 1
				} else {
					countMap[rawStr] = -1
				}
			}
			if countMap[rawStr] == 1 {
				break // go to next loop of i
			}
		}
	}
	return count
}