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 <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
using namespace std;
#define INF 100000000
#define MAXH 32
#define MAXW 32
typedef long long ll;
typedef pair<int, int> P;

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

int w, h;
// hは縦方向 wは横方向
int wallh[MAXH][MAXW], wallw[MAXH][MAXW];
int d[MAXH][MAXW];

int main(void) {
    while (1) {
        cin >> w >> h;
        if (w == 0 && h == 0) break;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w-1; j++) {
                cin >> wallw[i][j];
            }
            if (i < h-1) {
                for (int j = 0; j < w; j++) {
                    cin >> wallh[i][j];
                }
            } else {
                for (int j = 0; j < w; j++) {
                    wallh[i][j] = 1;
                }
            }
        }
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                d[i][j] = -1;
            }
        }
        d[0][0] = 1;
        queue<P> que;
        que.push(make_pair(0, 0));
        while (!que.empty()) {
            P now = que.front(); que.pop();
            int y = now.first, x = now.second;
            // 右方向
            if (x < w-1 && wallw[y][x] == 0) {
                int nx = x + 1;
                int ny = y;
                if (d[ny][nx] < 0) {
                    d[ny][nx] = d[y][x] + 1;
                    que.push(make_pair(ny, nx));
                }
            }
            // 上方向
            if (0 < y && wallh[y-1][x] == 0) {
                int nx = x;
                int ny = y - 1;
                if (d[ny][nx] < 0) {
                    d[ny][nx] = d[y][x] + 1;
                    que.push(make_pair(ny, nx));
                }
            }
            // 左方向
            if (0 < x && wallw[y][x-1] == 0) {
                int nx = x - 1;
                int ny = y ;
                if (d[ny][nx] < 0) {
                    d[ny][nx] = d[y][x] + 1;
                    que.push(make_pair(ny, nx));
                }
            }
            // 下方向
            if (y < h-1 && wallh[y][x] == 0) {
                int nx = x;
                int ny = y + 1;
                if (d[ny][nx] < 0) {
                    d[ny][nx] = d[y][x] + 1;
                    que.push(make_pair(ny, nx));
                }
            }
        }
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                cout << d[i][j] << " ";
            }
            cout << endl;
        }
        if (d[h-1][w-1] < 0) cout << 0 << endl;
        else cout << d[h-1][w-1] << endl;
    }
    return 0;
}

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

typedef pair<int,int> P;

int d[31][31];
int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
enum{RIGHT,UP,LEFT,DOWN};

bool tate[30+1][30];
bool yoko[30][30+1];
int W,H;

bool canmove(int x,int y,int mx,int my,int d){
     if(mx<0||my<0||mx>=W||my>=H){
	  return false;
     }else{
	  switch(d){
	  case RIGHT:
	       if(tate[x][y])return false;
	       break;
	  case LEFT:
	       if(tate[x-1][y])return false;
	       break;
	  case DOWN:
	       if(yoko[x][y-1])return false;
	       break;
	  case UP:
	       if(yoko[x][y])return false;
	  }
	  return true;
     }
}

int bfs(){
  queue< pair<int,int> > que;

  for(int i=0;i<W;i++){
    for(int j=0;j<H;j++){
      d[i][j]=-1;
    }
  }

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

  while(que.size()){
    P p=que.front();
    que.pop();
    if(p.first==W-1&&p.second==H-1)break;
    for(int i=0;i<4;i++){
      int nx=p.first+dx[i],ny=p.second+dy[i];
      if(canmove(p.first,p.second,nx,ny,i)&&d[nx][ny]==-1){
	que.push(P(nx,ny));
	d[nx][ny]=d[p.first][p.second]+1;
      }
    }
  }
  return d[W-1][H-1];
}
	  
int main(){
     for(int i=0;i<30;i++){
	  for(int j=0;j<31;j++){
	       tate[j][i]=0;
	       yoko[i][j]=0;
	  }
     }
     while(cin>>W>>H,W||H){
	  for(int i=0;i<H;i++){
	       for(int j=0;j<W-1;j++){
		    cin>>tate[j][i];
	       }
	       if(i!=H-1){
		    for(int j=0;j<W;j++){
			 cin>>yoko[j][i];
		    }
	       }
	  }
  
	  int a=bfs();
	  /*for(int j=0;j<H;j++){
	       for(int i=0;i<W;i++){
		    cout<<d[i][j];
	       }
	       cout<<endl;
	       }*/
	  
	  if(a==-1)cout<<0<<endl;
	  else cout<<a+1<<endl;
     }
     return 0;
}