You are given a positive integer, ~N~. Determine the minimum number of digits of ~N~ which must be replaced with ~3~'s to make ~N~ divisible by ~3~.

Constraints

~1 \le N < 10^{1\,000\,000}~

Input Specification

The first line contains one integer, ~N~.

Output Specification

Output one line containing one integer, the minimum number of digits of ~N~ which must be replaced with ~3~'s to make ~N~ divisible by ~3~. It can be shown that it is always possible to make ~N~ divisible by ~3~.

Sample Input 1

31415

Sample Output 1

1

Explanation for Sample 1

If you replace the last digit of ~31415~ with a ~3~, you get ~31413~, which is divisible by ~3~. (~31413 = 3 \times 10471~)

It can be shown that this is the minimal number of digit replacements.

Sample Input 2

42

Sample Output 2

0

Explanation for Sample 2

~42~ is already divisible by ~3~, so no digit replacements are required.