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 Scala (2.11.7) (judge verdict: Runtime Error)

object Main {
  def main(args: Array[String]): Unit = {
    val lines = io.Source.stdin.getLines().toList
    println(solve(lines))
  }

  def solve(lines: List[String]): Int = {
    val list = lines(0).split("").map(_.toInt).toList
    list.filter(_ == 1).length
  }
}