计算可以添加到特定数字的最小的子字符串，怎么使用C语言的代码的编写的技术的过程的实现的方式

Problem Description
Give you two number a, b. Output the smallest number that can be added to a to contain the number b as a substring.

Input
The first line contains a single positive integer T( T <= 500 ), indicates the number of test cases.
For each test case: Two number a,b;
0 <= a <= 10^100, 0 <= b <= 10^7

Output
For each test case: output the case number as shown and the smallest number that satisfy the description.

Sample Input
2
9 1
9 2

Sample Output
Case #1: 1
Case #2: 3