Problem:
Score : 100 points

Problem Statement

Snuke prepared 6 problems for a upcoming programming contest.
For each of those problems, Rng judged whether it can be used in the contest or not.

You are given a string S of length 6.
If the i-th character of s is 1, it means that the i-th problem prepared by Snuke is accepted to be used; 0 means that the problem is not accepted.

How many problems prepared by Snuke are accepted to be used in the contest?

Constraints

The length of S is 6.

S consists of 0 and 1.

Inputs

Input is given from Standard Input in the following format:

S

Outputs

Print the number of problems prepared by Snuke that are accepted to be used in the contest.

Sample Input 1

111100

Sample Output 1

4

The first, second, third and fourth problems are accepted, for a total of four.

Sample Input 2

001001

Sample Output 2

2

Sample Input 3

000000

Sample Output 3

0

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
int main() {
	int ans, S = 0;
	scanf("%d",&S);
	for ( S; S > 0; S /=10 ) {
		ans = 0;
		if (S == 0) {
			break;
		}else if (S % 10 == 1) {
			ans += 1;
          	S -= 1;
		}
		S /= 10;
		//printf("%d\n", S);
	}
	printf("%d\n", ans);
	return 0;
}