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: Runtime Error)

function main(input){
  let count = 0;
  const args = input.trim().split('');
  const num1 = args[0];
  const num2 = args[1];
  const num3 = args[2];
  
  if(num1 ==='1' ){
    count += 1;
  };
  if(num ==='1'){
    count += 1;
  };
  if(num3 ==='1'){
    count += 1;
  };
  console.log(count); 
};

main(require('fs').readFileSync('/dev/stdin', 'utf8'));