Ahmed and Mohamed love friends numbers – they say number x is friend to number y if and only if X contains number of digits equal to number of digits in Y. ex : 123 is friend to 457 , 1000 is friend to 9999 But 789 is NOT friend with 10 .

Ahmed and Mohamed decide to play a game, they choose randomly 2 friend numbers and count the number of different digits.

Ex: 1) 123 and 457 are different in 3 digits (because (1) is not the same to its corresponding digit (4) , (2) is not same to its corresponding digit (5) … and so on .

Ex: 2) 123, 145 are different in 2 digits. Given 2 friend numbers count the number of differences between their digits.

Input

Two space-separated friend numbers X and Y, (0<=X, Y<=1000000000)

Output

The number of different corresponding digits.

Example

Input:
10000 15678

Output:
4