Go: package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		w, h := io.NextInt(), io.NextInt()
		if w == 0 {
			break
		}
		xWall := make([][]int, h)
		yWall := make([][]int, h)
		for i := 0; i < h; i++ {
			xWall[i], yWall[i] = make([]int, w), make([]int, w)
			for j := 0; j < w; j++ {
				xWall[i][j], yWall[i][j] = -1, -1
			}
		}
		for i := 0; i < h*2-1; i++ {
			if i%2 == 0 {
				for j := 0; j < w-1; j++ {
					xWall[i/2][j] = io.NextInt()
				}
			} else {
				for j := 0; j < w; j++ {
					yWall[i/2][j] = io.NextInt()
				}
			}
		}
		//io.Println(bfs(w, h, xWall, yWall))
		fmt.Println(bfs(w, h, xWall, yWall))
	}
}

type P struct {
	x, y int
}

func bfs(w, h int, x, y [][]int) int {
	d := make([][]int, h)
	for i := 0; i < h; i++ {
		d[i] = make([]int, w)
	}
	q := list.New()
	q.PushBack(P{0, 0})
	d[0][0] = 1

	for q.Len() != 0 {
		pos := q.Remove(q.Front()).(P)
		if pos.x == w-1 && pos.y == h-1 {
			break
		}
		if pos.x > 0 && x[pos.y][pos.x-1] == 0 && d[pos.y][pos.x-1] == 0 {
			d[pos.y][pos.x-1] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x - 1, pos.y})
		}
		if pos.x < w-1 && x[pos.y][pos.x] == 0 && d[pos.y][pos.x+1] == 0 {
			d[pos.y][pos.x+1] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x + 1, pos.y})
		}
		if pos.y > 0 && y[pos.y-1][pos.x] == 0 && d[pos.y-1][pos.x] == 0 {
			d[pos.y-1][pos.x] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x, pos.y - 1})
		}
		if pos.y < h-1 && y[pos.y][pos.x] == 0 && d[pos.y+1][pos.x] == 0 {
			d[pos.y+1][pos.x] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x, pos.y + 1})
		}
	}
	return d[h-1][w-1]
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <stdio.h>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <iostream>
#include <set>
typedef long long int ll;
typedef unsigned long long int ull;
#define BIG_NUM 2000000000
#define MOD 1000000007
#define PRIME1 99999883
#define PRIME2 99999893
#define EPS 0.00000001
#define NUM 48
using namespace std;

struct Info{
	Info(){
		leftWall = false;
		underWall = false;
	}
	bool leftWall,underWall;
};

struct Data{
	int row,col,count;
	bool check[30][30];
};

int W,H;
int div_row[4] = {-1,0,0,1},div_col[4] = {0,-1,1,0};

bool rangeCheck(int row,int col){
	if(row >= 0 && row <= H-1 && col >= 0 && col <= W-1)return true;
	else{
		return false;
	}
}

void func(){
	int tmp;

	Info table[H][W];
	int firstTime[H][W];

	for(int i = 0; i < H; i++){
		for(int k = 0; k < W; k++)firstTime[i][k] = BIG_NUM;
	}

	for(int i = 0; i < H-1; i++){
		for(int k = 0; k < W-1; k++){
			scanf("%d",&tmp);
			if(tmp == 1)table[i][k+1].leftWall = true;
		}
		for(int k = 0; k < W; k++){
			scanf("%d",&tmp);
			if(tmp == 1)table[i][k].underWall = true;
		}
	}
	for(int k = 0; k < W-1; k++){ //?¨?????????±?????????1?????????
		scanf("%d",&tmp);
		if(tmp == 1)table[H-1][k+1].leftWall = true;
	}

	Data first;
	first.row = 0;
	first.col = 0;
	for(int i = 0; i < H; i++){
		for(int k = 0; k < W; k++)first.check[i][k] = false;
	}

	first.check[0][0] = true;
	first.count = 0;

	queue<Data> Q;
	Q.push(first);

	int ans = -1,next_row,next_col;

	bool FLG;

	while(!Q.empty()){

		if(Q.front().row == H-1 && Q.front().col == W-1){
			ans = Q.front().count;
			break;
		}

		for(int i = 0; i < 4; i++){
			next_row = Q.front().row+div_row[i];
			next_col = Q.front().col+div_col[i];
			FLG = false;
			if(rangeCheck(next_row,next_col) == true && Q.front().check[next_row][next_col] == false && firstTime[next_row][next_col] > Q.front().count+1){

				switch(i){
				case 0: //???
					if(table[next_row][next_col].underWall == false)FLG = true;
					break;
				case 1: //???
					if(table[Q.front().row][Q.front().col].leftWall == false)FLG = true;
					break;
				case 2: //???
					if(table[next_row][next_col].leftWall == false)FLG = true;
					break;
				case 3: //???
					if(table[Q.front().row][Q.front().col].underWall == false)FLG = true;
					break;
				}
			}

			if(FLG){
				Data new_data;
				for(int a = 0; a < H; a++){
					for(int b = 0; b < W; b++)new_data.check[a][b] = Q.front().check[a][b];
				}
				new_data.check[next_row][next_col] = true;
				new_data.row = next_row;
				new_data.col = next_col;
				new_data.count = Q.front().count+1;
				firstTime[next_row][next_col] = new_data.count;
				Q.push(new_data);
			}
		}
		Q.pop();
	}

	printf("%d\n",ans+1);
}

int main(){

	while(true){
		scanf("%d %d",&W,&H);
		if(W == 0 && H == 0)break;

		func();
	}

    return 0;
}