Description

When learning addition, I found that "carrying" is particularly error-prone. Your task is to calculate how many times carrying is needed when adding two three-digit numbers. Your program should be able to process multiple sets of data continuously until it reads two 0s (which marks the end of input).

Input Format

Input two positive integers m and n (both m and n are three-digit numbers).

Output Format

Output how many times carrying is needed when adding m and n.

Sample

123 456
555 555
123 594
0 0

0
3
1