package main

import . "fmt"

func main() {
	var n int
	var s, t string
	Scan(&n,&s,&t)
	odd, even := 0, 0
	for i := 0; i < n; i++ {
		if s[i] != t[i] {
			even++
		}
		j := n-1-i
		if s[j] != t[i] {
			odd++
		}
	}
	switch {
		case even%2==0 && odd%2==1:
			Println(min(even, odd))
		case even%2==0:
			Println(even)
		case odd%2==1:
			Println(odd)
	}
}