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 <queue>
#include <utility>

#define inf 1000000000

using namespace std;

int h, w;
int map[35][35];
const int dx[] = {1, 0, -1, 0}, dy[] = {0, -1, 0, 1};
int dist[35][35];

void bfs()
{
  for(int x = 0; x < w; x++){
    for(int y = 0; y < h; y++){
      dist[x][y] = inf;
    }
  }
  dist[0][0] = 0;

  queue<pair<int, int> > Q;
  Q.push(make_pair(0, 0));

  int x, y, nx, ny;
  while(Q.size()){
    x = Q.front().first;
    y = Q.front().second;
    Q.pop();
    for(int i = 0; i < 4; i++){
      if(map[x][y] & (1<<i)){
        continue;
      }
      nx = x + dx[i], ny = y + dy[i];
      if(nx < 0 || nx >= w; ny < 0 || ny >= h) continue;
      if(dist[nx][ny] < inf) continue;
      dist[nx][ny] = dist[x][y] + 1;
      Q.push(make_pair(nx, ny));
    }
  }


}

int main(void)
{
  while(1){
    cin >> w >> h;
    if(w == 0 && h == 0) break;

    for(int x = 0; x < w; x++){
      for(int y = 0; y < h; y++){
        map[x][y] = 0;
      }
    }

    for(int y = 0; y < h; y++){
      int t;
      for(int x = 0; x < w-1; x++){
        cin >> t;
        if(t == 1) map[x][y] |= (1<<0), map[x+1][y] |= (1<<2);
      }
      if(y != h-1){
        for(int x = 0; x < w; x++){
          cin >> t;
          if(t == 1) map[x][y] |= (1<<3), map[x][y+1] |= (1<<1);
        }
      }
    }

    bfs();

    if(dist[w-1][h-1] >= inf) dist[w-1][h-1] = -1;
    cout << dist[w-1][h-1]+1 << endl;
  }

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

// macro
#define rep(i,n) for(i=0;i<n;i++)
#define ll long long
#define all(v) v.begin(), v.end()

// code starts
#define INF 10000000
typedef pair<int,int> P;

int main()
{
  int w,h;cin>>w>>h;
  while(w!=0||h!=0)
  {
    bool maps[h][w][4];//up,right,down,left
    int i,j,k;
    rep(i,h)rep(j,w)rep(k,4)maps[i][j][k]=false;
    rep(i,h)
    {
      maps[i][0][3]=true;
      maps[i][w-1][1]=true;
    }
    rep(i,w)
    {
      maps[0][i][0]=true;
      maps[h-1][i][2]=true;
    }
    maps[0][0][0]=false;
    maps[h-1][w-1][2]=false;
    rep(i,h*2-1)
    {
      if(i%2==0)
      {
        rep(j,w-1)
        {
          int num;cin>>num;
          if(num==1)
          {
            maps[i/2][j][1]=true;
            maps[i/2][j+1][3]=true;
          }
        }
      }
      else
      {
        rep(j,w)
        {
          int num;cin>>num;
          if(num==1)
          {
            maps[i/2][j][2]=true;
            maps[i/2+1][j][0]=true;
          }
        }
      }
    }
    int steps[h][w];
    rep(i,h)rep(j,w)steps[i][j]=INF;
    steps[0][0]=0;
    queue<P> q;
    queue<P> q2;
    vector<int> dh={-1,0,1,0};
    vector<int> dw={0,1,0,-1};
    q.push(make_pair(0,0));
    while(!q.empty())
    {
      while(!q.empty())
      {
        P now=q.front();
        q.pop();
        int nh=now.first;
        int nw=now.second;
        rep(i,4)
        {
          int toh=nh+dh[i];
          int tow=nw+dw[i];
          if(toh<0||toh>=h||tow<0||tow>=w)
          {
            continue;
          }
          if(maps[nh][nw][i])
          {
            continue;
          }
          if(steps[toh][tow]==INF)
          {
            steps[toh][tow]=steps[nh][nw]+1;
            q2.push(make_pair(toh,tow));
          }
        }
      }
      while(!q2.empty())
      {
        q.push(q2.front());
        q2.pop();
      } 
    }
    if(steps[h-1][w-1]==INF)cout<<0<<endl;
    else cout<<steps[h-1][w-1]+1<<endl;
    cin>>w>>h;
  }
}