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 <vector>
#include <queue>
#include <algorithm>

using namespace std;

const int INF = 1e9 + 10;

struct Search {
  int y, x, cost;
  Search(int y, int x, int cost): y(y), x(x), cost(cost) { }
};

int main() {
  while (true) {
    int w, h;
    cin >> w >> h;
    if (w + h == 0) {
      break;
    }
    vector<vector<bool>> b(2 * h + 1);
    vector<vector<int>> cost(h);
    for (int i = 0; i < 2 * h + 1; i++) {
      b[i] = vector<bool>(2 * w + 1);
    }
    for (int i = 0; i < h; i++) {
      cost[i] = vector<int>(w, INF);
    }

    for (int i = 0; i < 2 * h + 1; i++) {
      b[i][0] = true;
      b[i][2 * w] = true;
    }
    for (int i = 0; i < 2 * w + 1; i++) {
      b[0][i] = true;
      b[2 * h][i] = true;
    }
    
    for (int i = 0; i < 2 * h - 1; i++) {
      if (i % 2 == 0) {
        for (int j = 0; j < w - 1; j++) {
          int t;
          cin >> t;
          if (t == 1) {
            b[i + 1][2 * (j + 1)] = true;
          }
        }
      } else {
        for (int j = 0; j < w; j++) {
          int t;
          cin >> t;
          if (t == 1) {
            b[i + 1][2 * j + 1] = true;
          }
        }
      }
    }

    cost[0][0] = 0;
    queue<Search> que;
    que.push(Search(0, 0, 0));

    int dy[4] = { -1, 0, 1, 0 };
    int dx[4] = { 0, 1, 0, -1 };

    while (!que.empty()) {
      Search s = que.front(); que.pop();
      for (int i = 0; i < 4; i++) {
        int ny = s.y + dy[i];
        int nx = s.x + dx[i];
        if (ny < 0 || ny >= h) {
          continue;
        }
        if (nx < 0 || nx >= w) {
          continue;
        }
        if (i == 0 && b[2 * s.y][2 * s.x + 1]) {
          continue;
        }
        if (i == 1 && b[2 * s.y + 1][(s.x + 1) * 2]) {
          continue;
        }
        if (i == 2 && b[(s.y + 1) * 2][2 * nx + 1]) {
          continue;
        }
        if (i == 3 && b[2 * ny + 1][s.x * 2]) {
          continue;
        }

        if (s.cost + 1 < cost[ny][nx]) {
          cost[ny][nx] = s.cost + 1;
          que.push(Search(ny, nx, s.cost + 1));
        }
      }
    }

    if (cost[h - 1][w - 1] == INF) {
      cout << 0 << endl;
    } else {
      cout << cost[h - 1][w - 1] + 1 << endl;
    }
  } 

  return 0;
}

C++: #include<iostream>
#include<queue>
#include<iostream>
#include<cstdio>
#include<map>
using namespace std;
const int INF=-333;
int dx[4]={1,-1,0,0},dy[4]={0,0,1,-1};
struct masu{
bool ue,si,mi,hi;
};
int main(){
	int w,h;
	while(true){
	cin>>w>>h;
	if(w==0&&h==0)break;
	masu t[50][50];
	int ans[50][50];
	queue<pair<int,int> >bfs;
	for(int i=0;i<50;i++)for(int j=0;j<50;j++)t[i][j].ue=0,t[i][j].si=0,t[i][j].hi=0,t[i][j].mi=0,ans[i][j]=INF;
	int neko=0;
	for(int i=0;i<h*2-1;i++){
		int tmp;
		if(i%2==0)for(int j=0;j<w-1;j++){
		cin>>tmp;
		if(tmp==1)t[neko][j].mi=1,t[neko][j+1].hi=1;
		}
		else for(int j=0;j<w;j++){
		cin>>tmp;
		if(tmp==1)t[neko][j].ue=1,t[neko-1][j].si=1;
		}
		if(i==0)neko++;
		else if(i%2==0)neko++;
	}
	/*for(int i=0;i<h;i++){
	for(int j=0;j<w;j++){
	cout<<i<<" "<<j<<"  ";
	if(t[i][j].ue==1)cout<<"ue"<<" ";
	if(t[i][j].si==1)cout<<"sita"<<" ";
	if(t[i][j].mi==1)cout<<"migi"<<" ";
	if(t[i][j].hi==1)cout<<"hidari"<<" ";
	cout<<endl;
	}
	}*/
	ans[0][0]=0;
	pair<int,int> xxx(0,0);
	bfs.push(xxx);
	while(bfs.empty()==false){
	pair<int,int>tmp=bfs.front();
	bfs.pop();
	//cout<<tmp.first<<" "<<tmp.second<<endl; 
	int tf=tmp.first,ts=tmp.second;
	if(tf+1<h&&t[tf][ts].si==0&&ans[tf+1][ts]==INF){//下に行くことができかつ下に壁はない。
	ans[tf+1][ts]=ans[tf][ts]+1;
	bfs.push(make_pair(tf+1,ts));
	}
	if(tf-1>=0&&t[tf][ts].ue==0&&ans[tf-1][ts]==INF){//上に行けて上に壁はない
	ans[tf-1][ts]=ans[tf][ts]+1;
	bfs.push(make_pair(tf-1,ts));
	}
	if(ts+1<w&&t[tf][ts].mi==0&&ans[tf][ts+1]==INF){
	ans[tf][ts+1]=ans[tf][ts]+1;
	bfs.push(make_pair(tf,ts+1));
	}
	if(ts-1>=0&&t[tf][ts].hi==0&&ans[tf][ts-1]==INF){
	ans[tf][ts-1]=ans[tf][ts]+1;
	bfs.push(make_pair(tf,ts-1));
	}
	}
	if(ans[h-1][w-1]==INF)cout<<0<<endl;
	else cout<<ans[h-1][w-1]+1<<endl;
	}
	return 0;
}