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++: 
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.PriorityQueue;

public class Main{

	 static int array[][];
	 static int gi=0,gj=0;
     static	int h,w;
	static int wall_yoko[][];
	static int wall_tate[][];

	 public static void main(String[] args)throws Exception{

	 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));


	 while(true){

    String readLine = br.readLine();
    readLine = readLine.trim();
    String[] num = readLine.split("[\\s]+");

    w = Integer.parseInt(num[0]);
    h = Integer.parseInt(num[1]);

    if(w==0 && h==0)
    	return;


    wall_yoko = new int[h][w-1];
    wall_tate = new int[h-1][w];

    array = new int[h][w];

    for(int i=0;i<h;i++){
    	for(int j=0;j<w;j++){
    			array[i][j]=Integer.MAX_VALUE;
    	}}

    for(int i=0;i<h;i++){

    	//?¨?????£????????????????
    	readLine= br.readLine();
    	readLine = readLine.trim();
    	String[] yoko = readLine.split("[\\s]+");
    	for(int j=0;j<w-1;j++)
    		wall_yoko[i][j]=Integer.parseInt(yoko[j]);

    	//???????£????????????????
    	if(i<h-1){
    	readLine= br.readLine();
    	readLine = readLine.trim();
    	String[] tate = readLine.split("[\\s]+");
    	for(int j=0;j<w;j++)
    		wall_tate[i][j]=Integer.parseInt(tate[j]);
    	}
    }

    	//?????????????????¢?´¢????§?
        gi=h;
        gj=w;

    	search(0,0,0);

    	if(array[h-1][w-1] == Integer.MAX_VALUE)
    		System.out.println(0);
    	else
    		System.out.println(array[h-1][w-1]);



    	/* array??????????¢????
        for(int i=0;i<h;i++){
	    	for(int j=0;j<w;j++){
	        	System.out.print(" "+array[i][j] );


	    	}System.out.println("");
        }
*/


	 }//while1??????

}

	 public static void search(int i,int j,int count){

		 count++;

		 //??¢?´¢???????????????????????°????????????
		 if(array[i][j] <= count)
			 return;
		 //????????????????????????????????????????????????????????????????°????????????°??????????????´??°
		 if(array[i][j]>count)
			 array[i][j]=count;

		 PriorityQueue<Integer> queue = new PriorityQueue<Integer>();



		 //????????¢?´¢
		 try{
		 if(j+1<w && wall_yoko[i][j]==0)
			 search(i,j+1,count);
		 }catch(Exception e){}

		 //????????¢?´¢

		 try{
		 if(j-1>=0 && wall_yoko[i][j-1]==0)
			 search(i,j-1,count);
		 }catch(Exception e){}

		 //????????¢?´¢
		 try{
		 if(i+1<h && wall_tate[i][j]==0)
			 search(i+1,j,count);
		 }catch(Exception e){}
		 //????????¢?´¢
		 try{
		 if(i-1>=0 &&wall_tate[i-1][j]==0)
				 search(i-1,j,count);
		 }catch(Exception e){}



	 }

}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>

using namespace std;

#define rep(i,j) REP((i), 0, (j))
#define REP(i,j,k) for(int i=(j);(i)<(k);++i)
#define BW(a,x,b) ((a)<=(x)&&(x)<=(b))
#define MP(a, b) make_pair(a, b)
#define F first
#define S second
#define Y first
#define X second
#define INF 1 << 30

typedef pair<int, int> pi;
typedef pair<int, pi> pii;
typedef vector<int> vi;
typedef queue<int> qi;
typedef long long ll;

int w, h, maze[128][128], dy[] = {0,-1,0,1}, dx[] = {-1,0,1,0};;

int main(){
  while(scanf("%d%d", &w, &h) && w+h){
    rep(i, 2*h-1){
      rep(j, (i%2)?w:w-1) scanf("%d", &maze[i][j]);
    }

    map<pi, int>m;
    queue<pi>q;
    q.push(MP(0, 0));
    m[MP(0, 0)] = 1;
    int res = 1;
    while(!q.empty()){
      //      printf("%d\n", res);
      int qsize = (int)q.size();
      rep(i, qsize){
	pi now = q.front(); q.pop();
	//	printf("%d %d\n", now.Y, now.X);
	rep(d, 4){
	  int ny = now.Y + dy[d], nx = now.X + dx[d];
	  if(ny < 0 || nx < 0 || ny >= h || nx >= w || m.count(MP(ny,nx))) continue;
	  if(d == 0){
	    if(maze[now.Y*2][now.X-1]) continue;
	  }else if(d == 1){
	    if(maze[now.Y*2-1][now.X]) continue;
	  }else if(d == 2){
	    if(maze[now.Y*2][now.X]) continue;
	  }else if(d == 3){
	    if(maze[now.Y*2+1][now.X]) continue;
	  }

	  //	  printf("%d %d\n", ny, nx);
	  m[MP(ny, nx)] = 1;
	  q.push(MP(ny, nx));
	  if(ny == h-1 && nx == w-1){
	    printf("%d\n", res+1);
	    goto e;
	  }
	}
      }
      res++;
    }
    puts("0");
  e:;
  }
  return 0;
}