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 Perl (5.26.1) (judge verdict: Accepted)

use v5.26; # strict say state biwise
use warnings;
use List::Util qw(reduce any all none notall first max maxstr min minstr product sum sum0 pairs unpairs pairkeys pairvalues pairfirst pairgrep pairmap shuffle uniq uniqnum uniqstr);

sub pow {
  my $d = shift;
  if ($d == 0) {
    1;
  } elsif ($d == 1) {
    10;
  } elsif ($d % 2 == 1) {
    (10 * pow($d - 1)) % 2019;
  } else {
    (pow($d / 2) ** 2) % 2019;
  }
}
my @s;
{
  chomp (my $in = <STDIN>);
  @s = split '', $in;
}
my $ans = 0;
my (@dp, @dpmod);
$dp[0] = 1;
for my $i (1..scalar(@s)) {
  my $t = $s[-$i];
  $dpmod[$i] = ($t * pow($i) + $dpmod[$i - 1]) % 2019;
  $ans += $dp[$dpmod[$i]];
  $dp[$dpmod[$i]]++;
}
say $ans;