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 Rust (1.42.0) (judge verdict: Accepted)

use std::io::stdin;
fn main() {
    let mut st = String::new();
    stdin().read_line(&mut st).unwrap();
    let s:Vec<char> = st.trim().chars().collect();
    let mut ten = 1;
    let mut c:usize = 0;
    let mut r:[i64;2020] = [0;2020];
    let m = s.len() as usize;
    for i in 1..m+1 {
        let x = (s[m-i] as usize)-48;
        c = (c+x*ten)%2019;
        r[c] += 1;
        ten = (ten*10)%2019;
    };
    let mut result:i64 = 0;
    for i in 0..2019 {
        if &1 < &r[i] {
            result += (r[i]-1)*r[i]/2
        };
    };
    result += r[0];
    println!("{}", result);
}