# Test

Time limit: 2 seconds
## Problem

Given a positive integer N >= 1, how many
integers within the range [1,N] are multiples of 3?

## Input

The input consists of a number of lines.
Each line contains a positive integer 1 <= N <= 1,000,000,000.
The last line contains a single integer 0. Do not process the last line.

## Output

For each input N, print the number of integers within
the range [1,N] that are multiples of 3.

## Sample Input

1
2
3
4
5
6
0

## Sample Output

0
0
1
1
1
2

## Author

Ho Leung