Xiaoqiang wrote a decimal number , but some of the handwriting has been blurred (we replaced it with ?). Now given another decimal number with the same number of digits, he wants to know how many possibilities make .
The first line is a positive integer , indicating the number of data groups; in each group of data, the first line is a decimal number within 16 digits, how many of them ? ; The second line is a decimal number with the same number of digits.