Test

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

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