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"
	"math"
)

func main() {
	var s string
	fmt.Scan(&s)
	
	snum := make([]int, len(s))
	
	for i := 0; i < len(s); i++ {
      snum[i],_ = strconv.Atoi(string(s[i]))
	}
	
	cnt := 0;
	for i := 0; i < len(s)-1; i++ {
		for j := i+3; j < len(s); j++ {
          if digits(snum[i:j+1]) % 2019 == 0 {
          	cnt++
          }
		}
	}
	fmt.Println(cnt)
}

func digits(num []int) int {
	ans := 0
	for i := 0; i < len(num); i++ {
      ans += int(math.Pow(10,float64(len(num)-1-i))) * num[i]
	}
	return ans
}