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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

      PROGRAM A
      IMPLICIT NONE
      INTEGER :: input(3),ans
      INTEGER :: index
      
      
      read'(I1,I1,I1)', input(1),input(2),input(3)
      
      ans = 0
      DO index = 1,3
        IF(input(index)==1)THEN
        ans = ans + 1
        END IF
      END DO
      
      print'(I0)',ans
      
      END PROGRAM