You are given 2 strings A and B of the same length N. A contains '0', '1', and '?'; B contains only '0' and '1'. Your task is to find minimum cost of transforming A into B by performing sequence of allowed operations with string A. Following operations are allowed:
Note that you are not allowed to apply these operations in B.
Input
The first line contains T - the number of test cases. Then T test cases follow.
Each test case consists of several lines.
Output
For each test, print the minimum cost in one line.
Constraints