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 (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var rdr = bufio.NewReaderSize(os.Stdin, 10000000)

func readLine() string {
	buf := make([]byte, 0, 10000000)
	for {
		l, p, err := rdr.ReadLine()
		if err != nil {
			panic(err)
		}
		buf = append(buf, l...)
		if !p {
			break
		}
	}
	return string(buf)
}

func main() {
	str := readLine()
	count := 0
	targetLen := 5
	if len(str) > 4 {
		for targetLen <= len(str) {
			for i := 0; i < len(str)-targetLen+1; i++ {
				slice := str[i : i+targetLen]
				num, _ := strconv.Atoi(slice)
				if num%2019 == 0 {
					count++
				}
			}
			targetLen++
		}
	}

	fmt.Println(count)
}