Let x and y be two strings over some finite alphabet A. We would like to transform x into y allowing only operations given below: Deletion: a letter in x is missing in y at a corresponding position. Insertion: a letter in y is missing in x at a corresponding position. Change: letters at corresponding positions are distinct Certainly, we would like to minimize the number of all possible operations. Illustration AGTAAGTAGGC ||| |||| AGTCTGACGC Deletion: ∗ in the bottom line Insertion: ∗ in the top line Change: when the letters at the top and bottom are distinct This tells us that to transform x = AGTCTGACGC into y = AGTAAGTAGGC we could be required to perform 5 operations (2 changes, 2 deletions and 1 insertion). If we want to minimize the number operations, we should do it like AGTAAGTAGGC ||| |||| AGTCTGACGC and 4 moves would be required (3 changes and 1 deletion). In this problem we would always consider strings x and y to be fixed, such that the number of letters in x is m and the number of letters in y is n where n ≥ m. Assign 1 as the cost of an operation performed. Otherwise, assign 0 if there is no operation per- formed. Write a program that would minimize the number of possible operations to transform any string x into a string y. Input Input contains several datasets. Each dataset consists of the strings x and y prefixed by their respective lengths, one in each line. Output For each dataset, an integer representing the minimum number of possible operations to transform any string x into a string y. Sample Input 10 AGTCTGACGC 11 AGTAAGTAGGC
2/2 Sample Output 4