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: Accepted)

object Main{
  def main(args: Array[String]){
    if (sys.env.getOrElse("TEST", "")=="1"){
      println(test());
    }else{
      val input=io.Source.stdin.getLines().mkString("\n");
      println(solve(input).trim());
    }
  }

  def solve(input:String):String={
    input.split("").filter(_=="1").size.toString()
  }

  val tests=List("""101""" -> """2""",
    """000""" -> """0""");

  def test():String= {
    return tests.map{case (i,o)=>(i.trim(),o.trim())}.zipWithIndex.map{case ((input,outputExpect),i)=>{
      val output=solve(input).trim();
      s"test${i+1}:"+(if(output==outputExpect){
        "Passed"
      }else{
        s"Failed\nexpect:\n${outputExpect}\noutput:\n${output}"
      })
    }}.mkString("\n");
  }
}