// No.1183 コイン遊び
package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const NMAX = 1_000_000

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Buffer(make([]byte, NMAX*2+2), NMAX*2+2)

	sc.Scan()
	N, _ := strconv.Atoi(sc.Text())

	sc.Scan()
	A := sc.Text()
	sc.Scan()
	B := sc.Text()

	diff0, count := false, 0
	for i := 0; i < N; i++ {
		diff := A[2*i] != B[2*i]
		if diff && !diff0 {
			count++
		}
		diff0 = diff
	}
	fmt.Println(count)
}