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 C# (.NET Core 3.1.201) (judge verdict: Time Limit Exceeded)

using System;
using System.Linq;
using System.Numerics;
using System.Threading.Tasks;
using System.Xml;

namespace ConsoleApp18
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();

            BigInteger cnt = 0;
            object locked = new object();
            Parallel.For(0, str.Length, i =>
           {
               for (int j = i; j < str.Length; j++)
               {
                   if (j - 1 + 1 < 3) continue;
                   var str2 = str.Substring(i, j - i + 1);
                   BigInteger n = BigInteger.Parse(str2);
                   if (n % 2019 == 0)
                       lock (locked)
                       {
                           cnt++;
                       }
               }
           });
            Console.WriteLine(cnt);

        }
    }
}