Given two numbers A and B, the task is to find the number of carry operations required when two numbers are added
Note: Both numbers are always of the same length.

Example 1:
Input:
A = 1234
B = 5678
Output:
2
Explanation:
1234
+
5678

6912

4+8 = 2 and carry 1
carry+3+7 = carry 1
carry+2+6 = 9, carry 0
carry+1+5 = 6
So, there are 2 Carry Operations.
Example 2:
Input:
A = 555
B = 555
Output:
3
Explanation:
555
+
555

1110

5+5 = 0 and carry 1
carry+5+5 = 0 carry 1
carry+5+5 = 0, carry 1
So, there are 3 Carry Operations.

Your Task:
You don't need to read input or print anything. Your task is to complete the function countCarry() which takes two Integers A and B and returns the answer.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)

Constraints:
1 <= A, B <= 10^{18}

见题面

见题面