Game of Strings

You are given two non-empty strings S and T of equal length. S contains '0', '1', '?' and T contains '0' and '1'. You have to convert S into T in minimum number of moves. There are 3 types of move you can apply to the string each costing 1 points. 1) You can change a '?' in S to '0' or '1' 2) You can swap any two characters in S 3) You can change a '0' in S to '1' Input The first line of t