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() {
    char a,b,s;
    scanf("%c%c%c",&a,&b,&s);
    if(a=='1'&&b=='1'&&s=='1'){
        printf("3\n");
    } else if((a=='1'&&b=='1'&&s=='0')||(a=='1'&&b=='0'&&s=='1')||(a=='0'&&b=='1'&&s=='1')){
printf("2");}
    else if((a=='0'&&b=='0'&&s=='1')||(a=='0'&&b=='1'&&s=='0')||(a=='1'&&b=='0'&&s=='0')){
        printf("1\n");
    }else{
        printf("0\n");
    }
    return 0;
}