Problem:
Score : 100 points

Problem Statement

Snuke has a grid consisting of three squares numbered 1, 2 and 3.
In each square, either 0 or 1 is written. The number written in Square i is s_i.

Snuke will place a marble on each square that says 1.
Find the number of squares on which Snuke will place a marble.

Constraints

Each of s_1, s_2 and s_3 is either 1 or 0.

Input

Input is given from Standard Input in the following format:

s_{1}s_{2}s_{3}

Output

Print the answer.

Sample Input 1

101

Sample Output 1

2

A marble will be placed on Square 1 and 3.

Sample Input 2

000

Sample Output 2

0

No marble will be placed on any square.

Solution in JavaScript (node.js v5.12) (judge verdict: Accepted)

'use strict'

let Main = (input) => {
  let v = []
  v[0] = input.substr(0,1)
  v[1] = input.substr(1,1)
  v[2] = input.substr(2,1)
  let count = 0
  for(let i=0; i <= v.length-1; i++){
    if(v[i] == '1') count++
  }
  console.log(count)
}

Main(require("fs").readFileSync("/dev/stdin","utf8"))