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 C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>

int main(void){
  int p,s1,s2,s3,x;
  scanf("%d",&p);
  s1=p/100;
  s2=p/10-p/100*10;
  s3=p%10;
  x=0;
  if(s1==1){
    x=x+1;
  }
  if(s2==1){
    x=x+1;
  }  
  if(s3==1){
    x=x+1;
  }
  printf("%d",x);
}