Given a binary string S consisting of characters 0, 1, and ?. In one operation, you can:
- Change the character 0 to 1.
- Change the character ? to 0 or 1.
- Swap two characters.
Determine the minimum number of operations required to transform the string S into a binary string T.
### Input
- The first line contains the string S.
- The second line contains the string T.
### Output
- Print an integer representing the minimum number of operations.
### Constraints
- 1≤|S|≤300.
### Sample test
Input:
0?1?1001
Output:
3
