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 <bits/stdc++.h>

using namespace std;

#define INF 1e9
typedef pair<int,int> P;

int h,w;
int v[50][50][4];
int dx[4]={1,0,-1,0},dy[4]={0,-1,0,1};

int d[50][50];

int bfs(){
    queue<P> que;

    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++)d[i][j]=INF;
    }

    que.push(P(0,0));
    d[0][0]=0;

    while(que.size()){
        P p=que.front();que.pop();

        if(p.first==h-1 && p.second==w-1)break;

        for(int i=0;i<4;i++){
            int ny=p.first+dy[i],nx=p.second+dx[i];


            if(0<=nx && nx<w && 0<=ny && ny<h && d[ny][nx]==INF && v[p.first][p.second][i]==0){
                que.push(P(ny,nx));
                
                d[ny][nx]=d[p.first][p.second]+1;
            }
        }
    }

    return d[h-1][w-1];

}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    while(1){
        cin>>w>>h;

        if(w==0)break;

        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                for(int k=0;k<4;k++)v[i][j][k]=0;
            }
        }

        for(int i=0;i<2*h-1;i++){
            if(i%2==0){
                for(int j=0;j<w-1;j++){
                    int a;
                    cin>>a;
                    v[i/2][j][0]=a;
                    v[i/2][j+1][2]=a;
                }
            }
            else{
                for(int j=0;j<w;j++){
                    int a;
                    cin>>a;
                    v[i/2][j][3]=a;
                    v[(i/2)+1][j][1]=a;
                }
            }
        }

        int ans=bfs()+1;

        if(ans==INF+1)ans=0;

        cout<<ans<<endl;

    }

}

C++: #include<iostream> 
#include<vector>
#include<utility>
using namespace std;

unsigned int calc(unsigned int step,const pair<int,int>& cur,vector< vector<unsigned int> >& sht,const int& w,const int& h,vector< vector<int> >& vwall,vector< vector<int> >& hwall){
	unsigned int sub,ret=-1;
	if(cur.first==w-1&&cur.second==h-1)return step;
	if(sht[cur.second][cur.first]<=step)return -1;
	sht[cur.second][cur.first]=step;
	if(cur.first!=0){
		if(vwall[cur.second][cur.first-1]!=1){
			sub=calc(step+1,pair<int,int>(cur.first-1,cur.second),sht,w,h,vwall,hwall);
			if(sub<ret)ret=sub;
		}
	}
	if(cur.first!=w-1){
		if(vwall[cur.second][cur.first]!=1){
			sub=calc(step+1,pair<int,int>(cur.first+1,cur.second),sht,w,h,vwall,hwall);
			if(sub<ret)ret=sub;
		}
	}
	if(cur.second!=0){
		if(hwall[cur.second-1][cur.first]!=1){
			sub=calc(step+1,pair<int,int>(cur.first,cur.second-1),sht,w,h,vwall,hwall);
			if(sub<ret)ret=sub;
		}
	}
	if(cur.second!=h-1){
		if(hwall[cur.second][cur.first]!=1){
			sub=calc(step+1,pair<int,int>(cur.first,cur.second+1),sht,w,h,vwall,hwall);
			if(sub<ret)ret=sub;
		}
	}
	return ret;
}
int main(){
	while(true){
		int w,h;
		unsigned int ret;
		vector< vector<int> > vwall,hwall;
		vector< vector<unsigned int> > sht;
		cin>>w>>h;
		if(w==0)break;
		vwall.resize(h);
		hwall.resize(h-1);
		sht.resize(h);
		for(int y=0;y<h-1;y++){
			vwall[y].resize(w-1);
			hwall[y].resize(w);
			sht[y].resize(w);
			for(int x=0;x<w-1;x++){
				cin>>vwall[y][x];
			}
			for(int x=0;x<w;x++){
				cin>>hwall[y][x];
				sht[y][x]=-1;
			}
		}
		vwall[h-1].resize(w-1);
		sht[h-1].resize(w);
		for(int x=0;x<w-1;x++){
			cin>>vwall[h-1][x];
			sht[h-1][x]=-1;
		}
		ret=calc(1,pair<int,int>(0,0),sht,w,h,vwall,hwall);
		cout<<((ret==-1)?0:ret)<<endl;
	}
	return 0;
}