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<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<set>
#include<vector>
#include<map>

#define REP(i, n, N) for(ll i=(n); i<(N); i++)
#define RREP(i, n, N) for(ll i=(N-1); i>=n; i--)
#define CK(n, a, b) ((a)<=(n)&&(n)<(b))
#define ALL(v) (v).begin(),(v).end()
#define MCP(a, b) memcpy(b,a,sizeof(b))
#define p(s) cout<<(s)<<endl
#define p2(a, b) cout<<(a)<<" "<<(b)<<endl
#define v2(T) vector<vector<T>>
typedef long long ll;
using namespace std;
const ll mod = 1e9 + 7;
const ll inf = 1e18;

#define MAX_LEN 900

int main(){
    int w,h;
    while(1){
	    cin >> w >> h;
        int ans=0;
        
        //壁の配列作成
        if(w==0 && h==0)break;

        int wall[h*2-1][w*2-1];
        REP(i,0,h*2-1){
            REP(j,0,w*2-1){
                wall[i][j]=-1;
            }
        }
        REP(i,0,h*2-1){
            if(i%2==0){
                REP(j,0,w-1){
                    cin >> wall[i][j*2+1];
                }
            }else{
                REP(j,0,w){
                    cin >> wall[i][j*2];
                }
            }
        }

        int maze[h][w];
        REP(i,0,h){
            REP(j,0,w){
                maze[i][j]=0;
            }
        }

        maze[0][0]=1;
        int adx[4] = {1,-1,0,0};
        int ady[4] = {0,0,1,-1};
        REP(len,1,MAX_LEN){
            //新しいルートを開拓したかどうか判定
            bool flag=false;
            REP(x,0,w){
                REP(y,0,h){
                    if(maze[y][x]!=len)continue;
                    REP(i,0,4){
                        int nx=x+adx[i],ny=y+ady[i];
                        if(nx<0||nx>=w||ny<0||ny>=h)continue;
                        if(wall[y+ny][x+nx]==1)continue;
                        if(maze[ny][nx]!=0)continue;

                        if(ny==h-1 && nx==w-1){
                            ans=len+1;
                            goto LAST;
                        }
                        flag=true;
                        maze[ny][nx]=len+1;
                    }
                }
            }
            if(!flag)break;
        }
        /**
        REP(y,0,h){
            REP(x,0,w){
                cout << maze[y][x] << " ";
            }
            cout << endl;
        }
        **/
        LAST:
        p(ans);
    }
}

C++: 
#include <iostream>
#include <vector>
#include <iterator>
#include <string>
#include <sstream>
#include <limits.h>

using namespace std;

string GetStr()
{
	string str;
	getline(cin,str);
	return str;
}

vector<int> GetIntVector()
{
	string str;
	getline(cin,str);
	istringstream line( str );

	istream_iterator<int> iit(line);
	istream_iterator<int> iit_eof;

	vector<int> ret;

	for(;iit != iit_eof; iit++){
		ret.push_back(*iit);
	}

	return ret;
}


typedef struct _Size
{
	int w,h;

	bool IsZero(){return w == 0 || h == 0;}

	
	static struct _Size GetSize()
	{
		Size s;
		vector<int> vec = GetIntVector();
		s.w = vec[0];
		s.h = vec[1];
		return s;
	}

} Size;

void GoNextFloor(Size& s,vector<vector<int> >& vwhole,vector<vector<int> >& hwhole,vector<vector<int> >& floor,int x,int y,int step)
{
	floor[y][x] = step;
	if(y == s.h-1 && x == s.w-1) return ;

	step++;

	//ã
	if(y > 0 && hwhole[y-1][x] == 0 && floor[y-1][x] > step)
		GoNextFloor(s,vwhole,hwhole,floor,x,y-1,step);

	//º
	if(y < s.h - 1 && hwhole[y][x] == 0 && floor[y+1][x] > step)
		GoNextFloor(s,vwhole,hwhole,floor,x,y+1,step);

	//¶
	if(x > 0 && vwhole[y][x-1] == 0 && floor[y][x-1] > step)
		GoNextFloor(s,vwhole,hwhole,floor,x-1,y,step);

	//E
	if(x < s.w - 1 && vwhole[y][x] == 0 && floor[y][x+1] > step)
		GoNextFloor(s,vwhole,hwhole,floor,x+1,y,step);

	//SÄÌ×Ì°ðà¢½ÌÅAé
	return;
}

void EscapeMaze(Size& s)
{
	//cA¡ÌÇ(v,h)
	vector<vector<int> > vwhole,hwhole;

	vwhole.push_back(GetIntVector());
	for(int i = 0; i < s.h - 1; i++){
		hwhole.push_back(GetIntVector());
		vwhole.push_back(GetIntVector());
	}

	vector<vector<int> > floor(s.h);
	for(int i = 0; i < s.h; i++){
		floor[i].resize(s.w);
		for(int j = 0; j < s.w; j++){
			floor[i][j] = INT_MAX;
		}
	}

	GoNextFloor(s,vwhole,hwhole,floor,0,0,1);

	int ans = floor[s.h - 1][s.w - 1];
	ans = (ans == INT_MAX) ? 0 : ans;

	cout << ans << endl;
}

void B()
{
	Size size = Size::GetSize();
	while(!size.IsZero()){
		EscapeMaze(size);
		size = Size::GetSize();
	}
}

int main()
{
	B();

	return 0;
}