Problem Statement

There are coin rows $a,b$, each consisting of $N$ coins arranged in a row.
The states of $a,b$ are given by sequences $A,B$.
$A,B$ are sequences of length $N$ consisting of $0, 1$. When the $i$-th number is $1$, the $i$-th coin is heads, and when it is $0$, the $i$-th coin is tails.
From here, you want to turn the state of $a$ into the state of $b$ by performing some number of times the operation of choosing any $i,j$ ($1\leqq i\leqq j \leqq N$) and flipping the $j-i+1$ coins from the $i$-th through the $j$-th coin of $a$ (changing heads to tails and tails to heads for each coin).
Find the minimum number of operations you need to perform.

Input

$N$
$A_1\;\,A_2\;\,...\;\,A_N$
$B_1\;\,B_2\;\,...\;\,B_N$

The sequences $A, B$ are given separated by spaces.
$1\leqq N\leqq 10^6$
$A_i$ and $B_i$ are $0$ or $1$
All inputs are integers

Output

Output on one line the minimum number of operations required to bring the coins to the state of sequence $B$, followed by a newline at the end.

Sample

4
0 0 0 1
1 1 0 1

1

7
0 0 1 1 0 0 0
1 1 0 1 1 0 1

3

20
0 1 1 0 1 1 1 0 0 0 0 1 1 0 0 0 0 0 0 0
1 0 1 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 1

5