You are given two binary strings \(S\) and \(T\) of the same length \(N\). Your task is to make both the strings equal. Perform the following operation on string \(S\):

Select any substring of \(S\) then flip all 1's to 0 and flip all 0's to 1 of that substring.

Print the minimum number of operations you have to perform to make them equal.

Input format

• The first line contains a single integer \(N\) (\(1\le N\le 1e5\)) size of each string
• The second line contains a string \(S\) of length \(N\). 
• The third line contains a string \(T\) of length \(N\). 

Output format

Print a single integer denoting the minimum number of operations required to make both the strings equal.

Constraints

\(1\le N\le 1e5\)