Problem:
Score : 100 points

Problem Statement

Snuke prepared 6 problems for a upcoming programming contest.
For each of those problems, Rng judged whether it can be used in the contest or not.

You are given a string S of length 6.
If the i-th character of s is 1, it means that the i-th problem prepared by Snuke is accepted to be used; 0 means that the problem is not accepted.

How many problems prepared by Snuke are accepted to be used in the contest?

Constraints

The length of S is 6.

S consists of 0 and 1.

Inputs

Input is given from Standard Input in the following format:

S

Outputs

Print the number of problems prepared by Snuke that are accepted to be used in the contest.

Sample Input 1

111100

Sample Output 1

4

The first, second, third and fourth problems are accepted, for a total of four.

Sample Input 2

001001

Sample Output 2

2

Sample Input 3

000000

Sample Output 3

0

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 y:Vec<char> = st.trim().chars().collect();
    let x:Vec<i32> = y.into_iter().map(|x| x as i32 - 48).collect();
    let z:i32 = x.iter().sum();
    println!("{:?}",z);
}