题目描述 Children are taught to add multi-digit numbers from $ right-to-left $ one digit at a time. Many find the $ "carry" $ operation - in which a $ 1 $ is carried from one digit position to be added to the next - to be a significant challenge. Your job is to count the number of carry operations for each of a set of addition problems so that educators may assess their difficulty. 输入格式 Each line of input contains two unsigned integers less than $ 10 $ digits. 输出格式 For each line of input except the last, you should compute and print the number of carry operations that would result from adding the two numbers, in the format shown below. 输入样例 123 456 555 555 123 594 0 0 输出样例 No carry operation. 3 carry operations. 1 carry operation.