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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// // 整数の入力
		// int a = sc.nextInt();
		// // スペース区切りの整数の入力
		// int b = sc.nextInt();
		// int c = sc.nextInt();
		// // 文字列の入力
		// String s = sc.next();
		// // 出力
    // System.out.println((a+b+c) + " " + s);
    String s = sc.next();
    int ans = 0;
    for (char c : s.toCharArray()) {
      if (c == '1') ans++;
    }
    System.out.println(ans);
	}
}