Problem Description

Snuke prepared 6 problems for a programming contest. For each of the problems prepared by Snuke, Ringo decided whether to adopt them for the programming contest or not.

A string \( S \) of length 6 is given, where the \( i \)-th character being 1 indicates that the \( i \)-th problem prepared by Snuke is adopted, and 0 indicates that it is not adopted.

How many problems prepared by Snuke were adopted for the programming contest?

Input Format

The input is given from the standard input in the following format:

\( S \)

Output Format

Output the number of problems prepared by Snuke that were adopted for the programming contest.

Sample Input and Output

Sample Input #1

111100

Sample Output #1

4

Sample Input #2

001001

Sample Output #2

2

Sample Input #3

000000

Sample Output #3

0

Notes/Hints

Constraints

• The length of \( S \) is 6.
• \( S \) consists only of 0 and 1.

Sample Explanation 1

A total of 4 problems from the 1st, 2nd, 3rd, and 4th were adopted.

见题面 Input 部分

见题面 Output 部分