#include <bits/stdc++.h>
using namespace std;
int main(){
  string a;
  cin>>a;
  int n=0;
  for(int i=0;i<6;i++)if(a.at(i)=='1')n++;
  cout<<n<<endl;
}
### Prompt

Please provide a cpp coded solution to the problem described below:

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.

Examples

Input

111100


Output

4


Input

001001


Output

2


Input

000000


Output

0

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main(){
  string a;
  cin>>a;
  int n=0;
  for(int i=0;i<6;i++)if(a.at(i)=='1')n++;
  cout<<n<<endl;
}
```